# ph readings, dropchecker always green and aquasoil... any relationship?



## parotet

Hi, I set up my new tank 2 days ago. It's a 60 liter tank with 9 liters of Aquasoil Amazonia (around 6 liters of sand), pressurized Co2 and 48w T5 running now only 6 hours. I'm trying now to understand if my CO2 diffusion is correct. To do this, I borrowed a high quality pHmeter from work and I am also using a dropchecker.

The "problem" right now is that my DC is always green (I would say that it turns a bit lime in the middle of the light period, but not really sure). On the other hand what I have done is to note the ph values during these days.

I use Lily pipes and the outflow is quite submerged, doesn't break at all the surface. The ceramic diffuser (2 cm diameter) is in the opposite side of the outflow. I can see the tiny bubbles (0,5 bps/30bpm) nearly reaching the surface and then being transported to the back of the tank. It seems, at least watching the plants and water moving, that the flow is not bad.


tap water pH (I only use tap water): 7.6 and very hard water (don't have test but my area is famous for that)

22h: 6.90
(no readings, just sleeping )
9h: 6.74 (CO2 ON)
10h: 6.67
11h: 6.62 (LIGHTS ON)
12h: 6.60
13h: 6.58
14h: 6.56
15h: 6.51 (CO2 OFF)
16h: 6.59
17h: 6.56 (LIGHT OFF)
18h: 6.55
Then it is suposed to rise to 6.8-6.9. I did this evening a 50% water change with tap water (ph: 7.6) at 19h and the value was after the WC was 6.95, so still far below my tap water values.

I asume that having probably KH values quite high, the pH drop will be of 0.5 maximum, which is more or less the case. Probably I should have these lowest values earlier (by switching on the CO2 earlier?).

On the other hand, it is the first time I use Aquasoil Amazonia and this is the second day, so there might be plenty of things happening in my water column. In the bag you can read that humic acids can be released, especially with alkaline water which is my case...Does it has something to do with my low ph values compared to tap water values?

And coming again to the ever green DC (even before CO2 is on, actually it never goes blue unless I take it outside the tank)... if my water had never reached ph7 during these two days, is it normal that my DC doesn't go to blue? Can you see a clear blue in your DC? When?

Sorry for so many questions and thank you in advance.

Jordi


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## Andy D

I am only just a beginner with CO2 so I hope someone else who knows more will be able to help but I think you are right in that the substrate is reducing the pH. I believe it lowers and buffers the pH and is a popular choice for shrimp keepers because of this.

I have very hard water (although I have started to soften it with RO) and my drop checker certainly went back to blue every morning. In fact I was getting a 1 pH drop from co2 on to lights on and my drop checker only ever went a dark green.

Given the starting pH reading I probably would expect more of a drop in pH was needed by lights on. Might need to up the injection rate?


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## parotet

Just an hour later of the 50% water change, the pH value is 6.75 (so dropped in one hour 0,2, without CO2 injection)... I will check if the DC goes blue tomorrow morning, but I notice more or less the same trend as yesterday.


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## Sacha

My drop checker is always green too. 

If you have your Co2 set up in perfect balance, the drop checker should be darkish green in the morning, and light green in the evening. 

The Co2 concentration of your tank will not drop too much overnight if the tank had lots of plants, because the plants respire at night, releasing Co2. 

If your DC turns blue outside of the tank, you can trust it. If it is always green, don't worry! You are doing everything right.


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## Spnl

I have London tap water, pH about 7.6 out of the tap, KH about 12-13 (JBL kit).
My drop checker is always green apart from going lime green to yellow by CO2 off at 6pm.

I think whether the drop checker goes blue or not overnight will depend on how much natural source of CO2 you have and how much surface agitation you have. According to a post on Cichlid forum, the main source of natural CO2 is the filter. Therefore, if you have good flow derived from massive filtration capacity, as many planted tanks have, you would expect lots of CO2 to be added overnight, whereas if your flow is mainly from circulation pumps, you might be gassing off overnight.
As Sacha says, as long the bromothymol blue goes blue when you take the drop checker out, if will be working OK.
Amazonia is supposed to reduce pH, so is a likely cause of your lower starting pH.

The size of pH drop to indicate the desired level do CO2 is a bit more complex. As a scientist, though not a chemist, I find some of the comments on here about how we "should" have a 1.0 drop in pH a bit over simplistic.
PH drops following CO2 addition due to addition of carbonic acid. The amount of pH drop for a given amount of acid added depends hugely on 2 things, buffering (for our purposes mainly KH) and starting pH.
A buffer resists change in pH, so reduces the pH change for a given amount of CO2.
Also, pH is a log scale, so the amount of acid to cause a 1.0 drop from 7 to 6 is 10x as much as needed to cause a 1.0 drop from 8 to 7.  
So your pH drop looks quite significant, though the drop checker should go lime green.

A good way  to see how much of the pH drop is due to CO2 as opposed to substrate, and how much CO2 is in your water is to take the water sample and leave it out of the tank overnight. I do this regularly, after Ceg suggested it in one of his priceless posts. My tank water is pH 7 ish in the morning, before CO2 on but will rise to 8 if left out all day, but drops to 6.6 by co2 off.
Your pH will drop after water change because tap water contains CO2; my tap water goes from 7.6 to over 8 if left to stand.


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## Sacha

Reading pH of the tank water is NOT an accurate way to measure Co2. 

I have only been on this forum a couple of days, but have seen loads of people talking about their co2 concentration in terms of a pH drop- how much the Co2 drops their pH. 

A drop checker is the most accurate way to measure co2 concentration. pH of tank water is affected by so many other things than Carbonic acid. Humic acids, ammonia (which is acidic), nitric acids, even some algaes, all can influence the pH. Therefore we need to read something which is constant and ONLY influenced by the co2 gas (and the resultant carbonic acid). The way we do that is with a contained amount of water of a known KH, which is not in contact with anything else that may alter its pH.


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## dw1305

Hi all, 





Sacha said:


> Reading pH of the tank water is NOT an accurate way to measure Co2....A drop checker is the most accurate way to measure co2 concentration. pH of tank water is affected by so many other things than Carbonic acid. Humic acids, ammonia (which is acidic), nitric acids, even some algaes, all can influence the pH. Therefore we need to read something which is constant and ONLY influenced by the co2 gas (and the resultant carbonic acid). The way we do that is with a contained amount of water of a known KH, which is not in contact with anything else that may alter its pH..





Spnl said:


> The size of pH drop to indicate the desired level do CO2 is a bit more complex. As a scientist, though not a chemist, I find some of the comments on here about how we "should" have a 1.0 drop in pH a bit over simplistic. PH drops following CO2 addition due to addition of carbonic acid. The amount of pH drop for a given amount of acid added depends hugely on 2 things, buffering (for our purposes mainly KH) and starting pH. A buffer resists change in pH, so reduces the pH change for a given amount of CO2. Also, pH is a log scale, so the amount of acid to cause a 1.0 drop from 7 to 6 is 10x as much as needed to cause a 1.0 drop from 8 to 7. So your pH drop looks quite significant, though the drop checker should go lime green.


 This is quite important, if you just aim for a certain level of pH drop you have every chance of asphyxiating your fish. As long as you use 4dKH solution, and a narrow range pH indciator (bromothymol blue), in the drop checker, the carbonate hardness of the tank water should be irrelevant.

Have a look at this post: <Ph drop & high alkalinity | UK Aquatic Plant Society>, it has lost the pH~ CO2~ dKH relationship chart, so I'll post it here.






Spnl said:


> According to a post on Cichlid forum, the main source of natural CO2 is the filter.


 If you have water with a large BOD (Biochemical Oxygen Demand, e.g. raw sewage, landfill leachate etc)) this is true, but I'd be very surprised if that is true for most aquarists, possibly once you get away from hugely over-stocked, non-planted, bare tanks for Mbuna etc. In tanks, which are not entirely reliant on the filter bacteria for biological filtration, I would expect that most of the CO2 comes from the respiration of the non-microbial bio-load (fish, plants etc.).  





Spnl said:


> Therefore, if you have good flow derived from massive filtration capacity, as many planted tanks have, you would expect lots of CO2 to be added overnight, whereas if your flow is mainly from circulation pumps, you might be gassing off overnight.


 This wouldn't be true, actually in nearly all biological filtration the volume of the filter media is practically irrelevant, it is the microbial biomass (of both nitrifying and ordinary heterotrophic bacteria) that produces the CO2.

Low BOD means low CO2 production. If you have plants they are  removing ammonia before it ever gets to the filter bacteria, the microbial biomass (and BOD) remains quite small.

Flow is relevant, but it doesn't matter whether it is from a power-head or a filter, more flow creates a larger gas exchange surface, and means that dissolved gas levels more closely match atmospheric levels. People who keep non-planted tanks are always teetering on the brink of disaster due to low oxygen/high CO2 levels, but for planted tank keepers the water is fully saturated with dissolved oxygen during the photo period when the plants are actively photosynthesizing.  

cheers Darrel


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## Samjpikey

I've been using the forum for a while now and the information i have been given is that a drop checker isn't the best method is to measure co2 accurately .... And by purely measuring the ph drop by itself is enough to measure co2 concentration. 
So does this mean I am using the wrong method ? 


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## Sacha

Be very wary of those pH/ KH charts, that is working on the assumption that there are NO other acids in the tank! 

And there almost always are other acids in the tank which influence pH. 

So yes, a drop checker is the way to go. Those charts are a good "rough guide" but definitely not accurate.


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## Samjpikey

I've never used the charts just led to believe that a ph drop of 1 by lights on was the rule of thumb . 


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## Sacha

Definitely not. 

A pH drop of 1 in a tank with KH 2 and a pH drop of 1 in a tank with KH 10 indicate completely different concentrations of Co2. 

As outlined by the chart


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## Samjpikey

Yea I understand that by all means . I understand about a difference in kh affects the amounts of co2 needed to saturate the water. 
What im saying is that if I have a consistent ph throughout the whole day( this stays at 7.6 even if I inject no co2 for 24 hrs )  when I inject co2 - this drops from co2 on - 7.6-6.6 1 hours later - surely that alone is telling how much co2 is entering the tank by making it more acidic . If no other factors have changed the ph previous to the co2 injection then this has to be true or do the other factors which affect the ph also   coincidentally take part at this time ?? 


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## Sacha

My point was really that a tank is not a stable and contained environment, there are lots of other things at play other than Co2 and KH.

In a drop checker, there are just three elements. pH, KH, and Co2. 

Therefore the drop checker is the most reliable way of measuring Co2. You can do whatever works for you, but there are many other factors in a tank that may affect your pH.


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## parotet

Thank you all for the answers... Ok, so as far as I understand:

1. I don't have to be worried if my DC doesn't turn blue.

2. I should try to see a lime green in my DC at least in the middle of the light period

3. DC is the best indicator as it won't be influenced by my substrate releasing right now humid acids (though I must learn to read properly dark green light green and lime green...), but pH meter can help me at least to check if within an hour (between CO2 on and lights on) I have a relevant pH drop which will be very probably due to an increase in the CO2 concentration.

4. The relevance of the pH drop using a pH meter in the water tank depends on the water kH. I think I should try to get at least 1.0 drop and check it with the DC color (which is not influenced as it works with a fix kH) at the end of the photoperiod to see if I would be gazing my fishes or if this drop is not enough.

My pH values and DC colors are the same as yesterday for the moment, even if I began to inject CO2 (0.5 bps) this morning 30 minutes before. I will try first to go to 1 bps and monitor the DC color and pH drop within between CO2 on and lights on.
If this doesn't work, I will try to place the ceramic diffuser under then flow lily pipe, just to check that it is not a problem of flow, but I think that in a 60 cm tank it should not be a problem (outflow in the opposite side of diffuser. I can see the bubbles going backwards and even again to the front of the tank).

Does it sound reasonable?


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## Sacha

Yes- absolutely. Good plan.


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## Samjpikey

This was mentioned in another thread on this forum . 
Hope it helps 


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## Victor

Sacha said:


> So yes, a drop checker is the way to go. Those charts are a good "rough guide" but definitely not accurate


 The chart was made to water inside your drop Checker. Never use your tank water as reference.


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## Andy D

parotet said:


> 3. DC is the best indicator as it won't be influenced by my substrate releasing right now humid acids (though I must learn to read properly dark green light green and lime green...), but pH meter can help me at least to check if within an hour (between CO2 on and lights on) I have a relevant pH drop which will be very probably due to an increase in the CO2 concentration.



So why is the drop checker not affected by other acids? Surely any acid would have an impact on pH?


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## Samjpikey

What if your colour blind ??? Sorry just had to  


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## OllieNZ

Andy D said:


> So why is the drop checker not affected by other acids? Surely any acid would have an impact on pH?


The drop checker is isolated from the tank water by an air gap.


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## parotet

Ok, so I increased the bubble rate to 1 bps yesterday night and the injection of CO2 began two hours before lights went on this morning...

And the result is a change from green (probably dark green) to lime green in my DC that remained quite stable from lights on until now (some minutes to CO2 shut off and 2 hours to lights off). My pH reading indicates that there has been only a drop of 0.5, from 6.92 to 6.41
So my DC says "it is not bad", but the pH readings say "it could be better".

So, what do you think about it? Should I try to place the ceramic diffuser under the inflow to see if I can manage to have a more relevant pH drop (and probably a yellowish in my DC)? At least this would be a way to know where the limit (no fish on tank).


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## dw1305

Hi all, 





Sacha said:


> Be very wary of those pH/ KH charts, that is working on the assumption that there are NO other acids in the tank!





Victor said:


> The chart was made to water inside your drop Checker. Never use your tank water as reference.





OllieNZ said:


> The drop checker is isolated from the tank water by an air gap.


 The CO2~dKH~pH chart only works for the drop checker, for the reasons quoted. It only estimates dissolved CO2 (from the addition of H2CO3) because of the air gap, and you can use the chart because you know we have 4dKH carbonate hardness in the drop checker. 





parotet said:


> So my DC says "it is not bad", but the pH readings say "it could be better".





parotet said:


> tap water pH (I only use tap water): 7.6 and very hard water


You can ignore the pH fall, in very hard water you are going to need to add huge amounts of CO2 to drop the pH of the tap water. If you increase the BPS you should see the drop checker become lighter. At the moment the fresh active soil is suppressing the pH, because it is exchanging alkaline cations (K+, Ca++ etc) for H+ ions, but because this is cation exchange, at some point equilibrium will be reached, this will stop and the pH will rise. At the moment you have two sources of acids  in the tank water, the H+ ions from ion exchange in the active substrate and the  H2CO3 from the added CO2.

Looking at the chart, if you had dKH = 20  in the tank water, you would need to add 120ppm of CO2 to drop the pH from pH7.6 to pH6.6.

Your initial pH is pH7.6 because you have a large amount of carbonate buffering (H+ ion acceptors), you can check this by adding any acid ("H+ ion donor", vinegar will do), and you will have to add quite a lot of acid before the pH of the water starts to drop.

cheers Darrel


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## ian_m

Be careful if you accidentally contaminate your drop checker water during tank maintenance it can cause it to change colour. Didn't really have an issue with my glass drop checker, but with my JBL plastic one I have found it green (should have been blue) after refilling tank with water during maintenance. Probably got tank water in it.

Replacing the indicator solution after washing it out and drying it and all back to correct changing colours.


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## parotet

dw1305 said:


> Looking at the chart, if you had dKH = 20 in the tank water, you would need to add 120ppm of CO2 to drop the pH from pH7.6 to pH6.6.


 
Thank you Darrel. Yes, I know my pH readings quite well as I borrowed a pHmeter from work, but honestly I have never bought a test for my aquarium, so I don't really know the dKH. As mentioned, the area where I live has very hard water.
I found on the internet a water test done by the water company in my city. I cannot tell which number is the KH and GH Reading the results... (dureza = hardness in Spanish)









ian_m said:


> Be careful if you accidentally contaminate your drop checker water during tank maintenance it can cause it to change colour. Didn't really have an issue with my glass drop checker, but with my JBL plastic one I have found it green (should have been blue) after refilling tank with water during maintenance. Probably got tank water in it. Replacing the indicator solution after washing it out and drying it and all back to correct changing colours.


 
Thank you Ian. Yes, this was one of the first things I did. Two reagent changes in 3 days.

Cheers,
Jordi


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## dw1305

Hi all,





parotet said:


> I cannot tell which number is the KH and GH Reading the results... (dureza = hardness in Spanish).


 You can't differentiate dKH and dGH (non-permanent & permanent hardness) from the given value, and the unit is "F", which suggests that it is "degrees French". One degree French is defined as 10 mg/L (so 10 ppm) CaCO3. Your value of 49.4oF is approximately 29 dGH, and that is very hard water.

The workings for different units are here: <How Do I Work Out K/Mg/Ca in Tap Water? | UK Aquatic Plant Society>, but because you have high levels of sulfate, you can't assume that all your calcium is from CaCO3.

The conductivity is really high as well 986microS and the TDS 698ppm, again reflecting a large total number of ions in solution.

cheers Darrel


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## Sacha

I find it very hard to believe that anyone has a TDS of 698- there's been a miscalculation there I'm sure.


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## parotet

Thanks again, my DC keeps turning from dark green to lime green, but I see that with such hardness I cannot expect much more than a 0.5 drop in my pH in 2 hours.
As mentioned I'll try to put today the ceramic difusser under the inflow to see if I notice a more relevant drop... will keep you informed.


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## dw1305

Hi all





Sacha said:


> TDS of 698- there's been a miscalculation there I'm sure.


 It is really high, but should be right, "evaporated to dryness at 180oC". If you multiply 986 by 0.64 (usual estimation of TDS in ppm based upon the electrical conductivity) you get 631ppm TDS, so it wouldn't need a lot of non-ionic dissolved compounds (that would contribute to TDS but not EC) to get to 698.

cheers Darrel


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## tim

Ceg was active on a thread stating a 1 point ph drop by lights on was an indication of good levels of co2 but the op had soft water I'm sure it was also stated in the thread a 0.5-0.7 drop was more likely acceptable in hard water, I can not find the thread in question but I think people are becoming fixated on this 1 point drop without realising they may not actually need it.


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## Samjpikey

I have moderately soft water living in Devon , when I spoke directly to ceg he said in soft water a ph drop of 1.4 was a good target althought 1 was ok , he said that a ph drop of 1 was always seen as a good target to hit regardless , I can't recall him telling me to look at the drop checker . 
Cheers 


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## parotet

p





dw1305 said:


> The conductivity is really high as well 986microS and the TDS 698ppm, again reflecting a large total number of ions in solution


The conductivity right now is 1050 microS/cm... so even higher!



dw1305 said:


> You can't differentiate dKH and dGH (non-permanent & permanent hardness) from the given value, and the unit is "F", which suggests that it is "degrees French". One degree French is defined as 10 mg/L (so 10 ppm) CaCO3. Your value of 49.4oF is approximately 29 dGH, and that is very hard water.


Should be breeding cichlids instead of growing plants 




tim said:


> Ceg was active on a thread stating a 1 point ph drop by lights on was an indication of good levels of co2 but the op had soft water I'm sure it was also stated in the thread a 0.5-0.7 drop was more likely acceptable in hard water


Yes, I remember this post. I think it is also mentioned in the DC tutorial. For the moment I'm just playing with that and trying to understand what is happening in my tank and what happens if I increase the bubble rate, place the difuser under the inflow, etc. I am a biologist and I have the chance to borrow from work a HACH meter with pH, conductivity and LDO probes as well as some good kits (ammonia, nitrates, etc.). Not necessary at all, but just for fun. More things to do with my new little toy!


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## dw1305

Hi all, 





parotet said:


> Should be breeding cichlids instead of growing plants


That was exactly what I was thinking when I was posting the reply, not many people could keep and breed _Alcolapia <  Alcolapia alcalica (Soda Cichlid) — Seriously Fish>_ in their tap water. If Tanganyikan cichlids were more your thing? I've always had a bit of a soft spot for "Shellies".

The really interesting thing is that the active soil had suppressed the pH. If I'd known the water parameters before hand, I would have suggested that the water was probably too hard for the soil to have much effect. Looking at the print out it  would suggest that a lot of the salts are chlorides and sulphates which would add TDS, and could add hardness, but wouldn't effect pH. Gypsum mines locally perhaps?

cheers Darrel


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## Samjpikey

Sorry to keep posting on this thread , I'm subscribed and eager to get a better understanding of the whole thing . 

My dkh of my tank around 4-5 

This is the colour of my drop checker  2 hours after co2 on -lighting Mary vary to the colour in real time . 





I measured ph at 7 am before work - ph 7 (this could easily change as you all know ) 
I measure ph 2 hours after co2 on (co2 on at 2pm) - ph 6.2 . 
I have no algae right now , does it all look in check ? 
Thanks 


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## parotet

dw1305 said:


> That was exactly what I was thinking when I was posting the reply, not many people could keep and breed Alcolapia < Alcolapia alcalica (Soda Cichlid) — Seriously Fish> in their tap water. If Tanganyikan cichlids were more your thing?


Mmmmm... I like plants too much. Maybe in the future, but not now, unless I found cichlids that love plants and don't want to dig my soil plenty of nutrients.



dw1305 said:


> Gypsum mines locally perhaps?


Some patches around my city but quite far away... it's the land of limestones (and in some isolated places sandstone). Kaolinite mines could be the cause?


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## parotet

A little graph to show my progress with pH readings





Day 1: 0,5 bps with diffuser in the opposite side of the outflow pipe 
Day 2: 1 bps with diffuser in the opposite side of the outflow pipe
Day 3: 1 bps with diffuser under the inflow pipe

As you can see there is no difference between day 1 and 2, even if the bubble rate was doubled. Today with the diffuser under the inflow I have managed to have a more significant drop in the pH (it will reach this evening 0.5-0.7 for sure) but I cannot manage to have this drop when lights on but much later. I will try to switch on the CO2 tomorrow at least 3 hours before (now there's a difference of 2 hours between CO2 and lights on).
My DC goes always from green to lime green, maybe a bit earlier today (and probably to yellow this evening, who knows...)

Cheers,
Jordi


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## parotet

Hi again, new update of the pH readings graph. The new thing is that today (day 4) the CO2 was switched on 3 hours before lights went on to try reaching the maximum pH drop at lights on. But again, this only happened 3 hours later (in the middle of the light period). The other thing which is a bit surprising is the pH is rising at the end of the light period… it should not be like this, isn’t it? DC is, as usual, lime green at the end of the light period.






The challenge is still reaching the maximum pH drop at lights on… but also to avoid pH rise at the end of period light? To reach a more relevant drop? (in that case my DC will turn yellow for sure, my tap water seems liquid rock..). To do so, shall I increase the bubble rate or switch on the CO2 earlier? Or both ?


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## Samjpikey

Are you using a spray bar or lily pipe ?? 


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## parotet

Samjpikey said:


> Are you using a spray bar or lily pipe ??


I'm using lily pipes both for inflow and outflow. The tank is 60 cm long and I can see a gentle movement in nearly all the tank plants...
Bolbitis and java ferns (normal and trident) on the front left side (opposite side of the outflow) move quite a lot.





Please note that in that picture the diffuser is not under the inflow as it is now. The DC is also in the opposite side now and the outflow is now closer to the water surface...
Yes, and the stones will be there for a while because the redmoor wanted to float


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## Samjpikey

I was going to say maybe you should try a spray bar along the back , I know a lot (including myself) have great results with a spray bar but seeing your set up is very nicely set up it's probably not worth the bother  


Awesome tank 

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## parotet

Samjpikey said:


> I was going to say maybe you should try a spray bar along the back , I know a lot (including myself) have great results with a spray bar but seeing your set up is very nicely set up it's probably not worth the bother
> 
> 
> Awesome tank
> 
> Sent from my mobile telecommunications device


Well, if this way I can improve my CO2 levels I will do it... I have increased the bubble rate in order to see if I can notice any progress tomorrow. If it fails, the next step should be the spray bar. Anyway, I guess the spray bar will ensure a good distribution of the CO2, but there should be no difference with what I'm doing (injecting the gas to the inlet). The aim now is trying to reach the lowest pH earlier.
Distribution issues will come later, sure!


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## Samjpikey

If you can achieve a better distribution of co2 then the co2 saturation process could be more efficient dropping the ph even lower , this though could not always be the case , but then it could be  
I found I could achieve a lower ph level by lights on when my distribution was via a spray bar , I also have lowered the bubble rate.


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## parotet

Yes, you're right. I have been reading some old threads and the many people have solved this problem improving the flow, in most cases with a spraybar. I could even save some CO2 due to better efficiency (instead of increasing more and more the bubble rate). Will keep on with my test today and maybe I will try to reduce the amount of material in my Eheim 2215 to increase the outflow (it is now full of media to the top. I should leave it only with coarse sponge and ceramic rings and get rid of the other sponges).


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## Samjpikey

^^^ I would do exActly this , I wouldn't hesitate to remove 50% of the media and just leave in one sponge.
Be interested to see what results you get  
Cheers 


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## parotet

Hi again, new update. This time with the diffuser placed under the inflow (as previous days) but I increased the bubble rate. Not happy with the results because there has been a small pH drop, but once again, not on time. Moreover I feel like I’m losing part of the injected CO2. The inflow is not able to swallow all the bubbles and as a result some of them reach the surface (I would say a 20%). So definitely I looks like a flow problem rather that a rate problem.







First of all, I will get rid of half of the canister media, but this weekend I will look for cheap tubing to drill some holes and make a DIY spray bar... lots of fun with this issue!


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## Rob P

Your graphs are a bit more advanced than mine


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## parotet

That's what happens when you spend too many time in front of a computer  your brain works like an Excel file


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## parotet

It works, more flow was needed. I removed part of the media of my canister and...





more pH drop when light on. Next step: DIY spraybar.


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## Jon

Sacha said:


> Reading pH of the tank water is NOT an accurate way to measure Co2.
> 
> I have only been on this forum a couple of days, but have seen loads of people talking about their co2 concentration in terms of a pH drop- how much the Co2 drops their pH.
> 
> A drop checker is the most accurate way to measure co2 concentration. pH of tank water is affected by so many other things than Carbonic acid. Humic acids, ammonia (which is acidic), nitric acids, even some algaes, all can influence the pH. Therefore we need to read something which is constant and ONLY influenced by the co2 gas (and the resultant carbonic acid). The way we do that is with a contained amount of water of a known KH, which is not in contact with anything else that may alter its pH.


 
I couldn't help but respond to this..

Measuring the tanks ph IS the most accurate way in measuring co2.
The higher the water's kh, the more likely that the ph is effected from other sources of bicarbonates..this is true, and if we STRICTLY follow the ph/kh chart then you will likely not get an accurate measurement of co2 . However the ph/kh chart is not an exact science, similar to the drop checker, its an estimation of co2 concentrations, nobody is saying follow it exact, its essentially a starting point, like a drop checker.
When we use a ph meter(a good ph meter) we measure the tanks base ph, with no co2, then monitor the shift in ph, and using the kh/ph chart we can get close to our target co2. So essentially very similar to the drop checker, however this is where the accuracy of a ph meter greatly outweighs the drop checker. As we drive down the tanks ph, the more we drive it down, for each 0.1 ph shift, co2 shifts non linearly(you can see this in the ph/kh chart) and just 0.1 point can be a big difference in co2 concentration. For example, if we have a kh of 3, and our base ph is 7, we drive down the co2 to reach 30ppm were at around 6.5 ph, but lets say we have algae, poor plant growth etc. and we want to add say 10ppm more of co2, that's only around a 0.15 shift in ph, a very miniscule difference that's easily adjusted with a ph monitor, we dont have this accuracy in a drop checker. This isnt to say either that the 0.15 shift in ph will net exactly 10ppm more of co2, but that small adjustment can often times be the difference in a healthy aquarium or one covered in algae. Neither method is an exact science, but a ph meter is far better in monitoring co2 injection rates.


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## dw1305

Hi all, 





Jon said:


> When we use a ph meter(a good ph meter) we measure the tanks base ph, with no co2, then monitor the shift in ph, and using the kh/ph chart we can get close to our target co2. So essentially very similar to the drop checker, however this is where the accuracy of a ph meter greatly outweighs the drop checker. As we drive down the tanks ph, the more we drive it down, for each 0.1 ph shift, co2 shifts non linearly(you can see this in the ph/kh chart) and just 0.1 point can be a big difference in co2 concentration. For example, if we have a kh of 3, and our base ph is 7, we drive down the co2 to reach 30ppm were at around 6.5 ph, but lets say we have algae, poor plant growth etc. and we want to add say 10ppm more of co2, that's only around a 0.15 shift in ph, a very miniscule difference that's easily adjusted with a ph monitor, we dont have this accuracy in a drop checker.


 This is right, but with the proviso that pH meter's aren't the lowest maintenance bit of kit, and needed to be calibrated with pH4 and pH7 buffers before each use.You also may run into problems if the dKH of the tank water changes.

Have a look at "plantbrain's" post in this thread 
[URL="http://www.ukaps.org/forum/threads/ph-drop-high-alkalinity.30384/#post-321378"]Ph drop & high alkalinity[/URL]

cheers Darrel


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## parotet

I do use a pH meter calibrated each time... not the cheapest instrument, no. The one I use from work costs a fortune.
This afternoon a new update. In my case it is a way to fine-tune some CO2 issues...


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## Rob P

I use the £7.99 ebay yellow Ph pen lol, and calibrate occasionally with independently bought ph4 & 7 solutions. I have to say i've been impressed with how it retains calibration, having only had to make minor tweaks (like 0.2 at the most) in the 2 months i've been using it! 100 times better than trying to decipher liquid test results.


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## Samjpikey

I also use a £7.99 pen from eBay and I haven't once calibrated it , i have no idea if it needs it but I seem to be able to control my co2 levels with the results alongside the drop checker . 
Seems to work ok for me  


Sent from my mobile telecommunications device


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## parotet

Guess what? This was another spraybar thread! New update and more progress achieved regarding the absolute pH drop and the time needed for minimum value. It looks a bit impossible to me to have a more relevant pH drop (with the spraybar it’s 0.4, maybe could be around 0.5. Should seriously consider to make a KH and GH test to know how liquid rock is my tap water) as my DC is quite yellowish at the end of the light period. I don’t have critters for the moment but I would be a bit worried if I had them. More advantages of the spraybar: I can manage to have nice ripples in the water surface, gentle movement of all my plants (even the ones in the corners), the surface film I had these last days seems to have vanished and I reach better values with less CO2.
Let it flow!!!!









next steps: change the crappy Eheim green hook, see if the redmoors have decided no to float anymore... and watch it grow.


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## Rob P

Is it a DIY spraybar fitted into the Eheim sheperds crook? If it is and it's a 16/22 crook what material did you use to make it


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## parotet

Yes it is a 50 cm DIY spraybar fitted into the 12mm Eheim sheperds crook. I bought 1 meter of 12mm diameter PVC rigid tube (3.5€/meter) to try the configuration (how many holes and their size) and have at least 2 chances... but finally I only needed one (I read it in another thread: your outflow area must me more or less similar to the new outflow area, that is now 10 tiny holes. The water must hit the front glass). The PVC spraybar is attached to the hook with a small piece of green eheim tubing (12/16 mm). Much better if it not Green   I will consider to buy an acrylic spraybar (10€/meter if I am not wrong) that is like glass... (PVC is a bit blue compared to acrylic).
Anyway, if you go to a specialised plastic shop you will have any diameter for tubing. Suckers were purchased in a pet shop.


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## Rob P

Looks tidy


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## Samjpikey

What kind of sand are you using ??? 


Sent from my mobile telecommunications device


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## parotet

JBL river sand, not so white as JBL white sand.


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## Jon

dw1305 said:


> Hi all, This is right, but with the proviso that pH meter's aren't the lowest maintenance bit of kit, and needed to be calibrated with pH4 and pH7 buffers before each use.You also may run into problems if the dKH of the tank water changes.
> 
> Have a look at "plantbrain's" post in this thread <http://www.ukaps.org/forum/threads/ph-drop-high-alkalinity.30384/#post-321378>.
> 
> cheers Darrel


I agree, it is more expensive and you do need to ensure calibration, however it is far more accurate. I would never advise anyone to use a ph controller for injecting co2, if the kh changes then its easy to gas fish, or have something go wrong. however using a ph monitor as a means of adjusting co2 can be very accurate, especially when you get to very high co2 levels where drop checkers and bubble counts become unreadable.


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## parotet

Hi, new update but no more figures  , just mention that my DC goes blue every night now. May I asume that this is due to the ripples produced by the spraybar in the water surface? (loss of CO2) 
I kept measuring the pH during the last days and I have also noticed that  itis slowly going up, closer to the tap water values. I guess the Aquasoil is leaching less humic acids.

Now, trying to see if I can still improve the system:
CO2 inline diffusers | UK Aquatic Plant Society


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## hudsonpd

Hi everyone,

Interesting discussion. Thank you Parotet for starting it and giving such detailed information.

This is something I have been struggling with for a while! A year ago I was also given the advice to try and drop the PH by 1 point by the time lights went on. I was struggling to achieve this so I started the gas 3 hours before and switched it off 3 hours before lights off. However, this nearly led me to gassing all of my fish by the time the lights went out - as surely it is logical that if I can drop the PH by 1 within 3 hours then the subsequent 3 hours will drop it by a further point too? No?

Anyway, this weekend I read the threads about the CO2/PH/KH table quoted on this thread so took a sample of my water to the local Maidenhead Aquatics and they tested it for KH (a good idea Parotet, without any expense!) and they told be the KH was 7.5 (from a sample taken before lights or gas were on, should that make any difference).

PH is neutral at somewhere between 7 and 7.3 but I've not got a very accurate reading of that (my sample of water wasn;t big enough to test both and my kit goes up in .5 increments! doh!)

So, whilst my water is nowhere near as hard as yours, Parotet, it did get me thinking about the buffer zone. If I take the PH to be 7.2 and the KH to be 8 on this table, then surely to get to my target CO2 level, I only atually need to drop the PH to 6.9 to achieve it?

Currently I am dropping to beyond this by the time the gas goes off. Tonight it was reading at about 6.5-6.7 when I got home an hour after the gas had gone off. Which, according to the table is way too much?!

Can somebody please explain why, with this table and my drop checker reading lime green, do I need to drop the PH by 1 before lights go on?

Thanks
Paul


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## hudsonpd

PS. Also, can anyone tell me if the PH pen checkers or similar (shown below on ebay) are worth buying? Are they accurate?

I would like to do more detailed hourly tests like Parotet did but I only have a broad colour based test kit (0.5 increments) and my LFS doesn't have anything more detailed. They suggested a cheapish digital one.

 LCD Digital PH Hydroponic Pen Meter Pool SPA Aquarium Wine Water Tester Pen UK | eBay
OR
 Digital pH Meter Monitor Tester Replaceable Electrode Probe Solution x2 Aquarium | eBay
OR
 Waterproof Digital big LCD pH & Temperature Meter Tester 0~14pH °C °F IP65 | eBay


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## parotet

Hi Paul! Thank you for your reply. As you have noticed I am not an expert on this topic...  But this thread has been really interesting to learn and think about some of the things happening in my tank. I will try to explain the lessons I learnt playing with my pHmeter and DC.

Concerning the measures I did, I have to say that I borrow a (very expensive) pHmeter from work. It has to be calibrated before each measure but it gives an accuracy of 0.01. I think a cheap pH meter can be used to measure the trend of your pH, but when the drop is significant (let's say 1 point). Have a look at my graph and you will see that I managed to have maximum drops of 0.5, and some days it was less. That means that if I worked with a pH meter with an accuracy of 0.1 my measurements would have been very bad. So I guess it is a balance between what you are measuring and what equipment you can afford or borrow. The difference between these pHmeters can be very high (from 10 to 3,000 euros), and IMO it makes no sense to spend that money because we have other indicators... DC! 

Concerning the pH drop, it was explained by Darrel that the DC is a good estimation of the CO2 based also on pH drop but in an isolated and controlled chamber (the DC), thus what you can read is not affected by other acids in the water column. It really measures the CO2, but indirectly. A pH meter is useful and accurate but you should understand that some of the readings can be affected by humid acids or other substances on the tank... Note that my first reading at 7am is quite different from one day to another, especially now that aquasoil is not leaching that much substances. If KH changes, my pH reading will also be affected... The DC never lies, but it can be hard to read (really confusing sometimes to tell the difference from green, to lime and yellow).

The lesson I learnt is: use the pH meter for example to test which configuration is the best to reach the maximum drop when lights on (where to place the outflow, which kind of outflow, where to place the diffuser, etc.), check with the DC that you have a nice lime green when lights on but also check that it doesn't go yellow (I found for example with higher bps my DC was yellow at the end of the day), and finally don't be confused if you don't manage to reach 1 pH of drop. If your water is too hard, like mine, and if you finally manage to have such a drop you will be adding much more CO2 than needed (you will be gasing your fish. Have a look at the chart and see the CO2 values when dropping 1 point of pH in very hard water...)

Two other very important lessons learnt about CO2 in this forum... Flow and constant levels. If all the leaves in your tank move gently the CO2 gets everywhere (much better than having lots of CO2 in some areas and dead spots). About the amount of CO2 it seems that plants can get used to different levels of CO2 but they have serious difficulties to adapt to changing levels.

Once again, please note that I am just a newbie and these are very basic rules I have learnt and experienced in my tank, but maybe poorly explained.


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## hudsonpd

Thanks for your reply and summary Parotet - without wanting to be patronising, you have written an excellent summary and all learnt very fast by all accounts!

My difficulty is that easy growing plants grow well but other ones die within 2 weeks of buying. And everything on here has advised it is about getting the co2/light balance correct. However, on the CO2 front, I did indeed nearly gas my fish in exactly the scenario you described above.

And yet, I don't think my water is particular hard, more soft/medium I would think. But even with this, taking the reading of KH being 7.5 and a starting PH position of about 7.2-7.3, I surely don't need or should be looking for a drop of 1. The important thing to note here is I would have thought very few people should be - unless most tap water has a PH of over 7.5 or most water is medium-hard, in which case large drop in PH is needed but would be very hard to achieve!


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## ceg4048

hudsonpd said:


> However, on the CO2 front, I did indeed nearly gas my fish in exactly the scenario you described above.


Nearly gassing of fish is a result of poor execution of flow and distribution. The effect of good flow/distribution is to obtain a more homogeneous CO2 concentration across the tank. Everyone assumes that any point in the tank has the same CO2 as any other point in the tank. This idea is brought about by the fact that we normally only use a single point measurement in the tank at the location where the DC is mounted. The reading taken by the DC is immediately taken as a proxy measurement for all other points in the tank, and this is a very poor assumption.



hudsonpd said:


> But even with this, taking the reading of KH being 7.5 and a starting PH position of about 7.2-7.3, I surely don't need or should be looking for a drop of 1.


Yes, surely you should. The "Ph-delta" of 1 is just a guide. You may need to drop it more and you may be able to get away with less. But it's a good starting point that seems to work well for a majority.

If a pH drop of 1 in a KH 7.5 causes discomfort or fatality in the tank, then we can immediately conclude that either poor flow or poor distribution, or both, is the likely culprit. That information is based on personal experience and the experience of those who use this technique. Again, people become too rigid when applying, what we consider to be, simple guidelines, often run into conflict because they are not looking at a wide enough picture.

The need for the pH drop has nothing to do with the effects of pH, but rather has to do with the fact that the difference in the pH over the short span of time is mostly due to the effectiveness of the CO2 in dissolving. And it is actually very easy to drop the pH using CO2 in medium alkalinity water that you have.

The point is to forget about pH as a factor in plant or fish health. They really do not care very much about what the pH value is. They only care about WHY the pH is at it's present value. If the pH drop is due to a toxin, then they will suffer due to a toxin, not due to the effects of pH. If the pH drop is cause by an innocuous agent then the fish will not exhibit any aversion to the change in pH. CO2 is a weak acid and is therefore innocuous from an acidic perspective. Strong acids, like the stuff in "pH Down" type products are toxic because they contain toxic acids. A pH drop if 1 unit caused by pH Down type products causes injury to fish - because Nitric or Phosphoric acids are strong acids. Yet, people add these products to their tank all the time trying to "stabilize" or otherwise control pH.




hudsonpd said:


> Can somebody please explain why, with this table and my drop checker reading lime green, do I need to drop the PH by 1 before lights go on?


This is another misapplication of the table. The table cannot tell you how much CO2 is in the water at any one point. It cannot tell you how much of the acidity is caused by CO2 as opposed, for example to tannic acid leached from wood, or due to nitric acid caused by decay of organic substances in the water. Therefore, the value it returns, based on a single point reference is always going to overestimate the actual CO2 content. There can be hundreds of other acids in the tank in very small quantities. They all combine to produce a pH in the tank water. The table _assumes_ that all the acid in the water sample you are measuring is caused only by Carbonic acid which results from dissolved CO2.

In order to jump around this obstacle we take at least two readings and we assume that the DIFFERENCE in the reading is caused only by CO2 dissolving. That's not a 100% fact, but, there is not enough acid being produced by the tank to drive such a large difference. The component of humic, tannic and other organic or inorganic acids that contribute to the pH drop is miniscule when compared to the difference in acidity caused by the Carbonic acid. So by subtracting the pH values, one can then roughly calculate how much CO2 was added, because when you subtract, you are effectively subtracting out the component of tank-produced acids.



parotet said:


> Concerning the pH drop, it was explained by Darrel that the DC is a good estimation of the CO2 based also on pH drop but in an isolated and controlled chamber (the DC)


The DC is NOT a good indicator, but it is all we have, unless we are willing to shell out £1000 to buy a CO2 meter.

It's a LOT easier to use the pH pens, no matter how cheap or cheesy, but as Darrel would no doubt have cautioned, the pens should frequently be calibrated. Because of the fact that this mathematical obstacle of "taking into account the tank-produced acids is eliminated by reading the pH drop" looking at the data, especially when plotted on a graph gives us a very good picture of how the CO2 is behaving and how effective our flow/distribution CO2 dissolution is.


Cheers,


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## hudsonpd

As always Ceg, thank for your time and answer

So you are saying I need to take two ph readings in order to work out how co2 is dissolving? 

I will take a video at the wake if I can because the flow is good. The dissolving may be an issue I suppose but using an inline diffuser, it has never been really right. It may have clogged up slightly more recently but as I say I don't think co2 has never been quite right. The DC is always green wherever I put it (although it can be hard to see the colour differences)


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## ceg4048

Yes mate, this is the problem with the DC. Of course we have a DC user guide in the Tutorial section and we advocate it's use because it's a very simple tool, but it's just a test kit and we really cannot rely on test kits to have any kind of fidelity.

two ph readings in a span of time tells you what the difference in dissolved CO2 is. So if we take many readings over time, it will paint a more accurate picture of the dissolution during that time. Take a reading starting from when you first turn the gas on. Then, take subsequent readings every hour or even 1/2 hour for the duration of the photoperiod.

What you are looking for is to have the lowest pH "ideally" at exactly the time that the lights go on.

The assumption that the pH will continue to drop to lethal levels is not necessarily correct. That's because the plant will start to uptake CO2 into their tissues and will remove it from the water. Unfortunately, whhen flow and distribution are poor the gas tends to collect/concentrate in some areas, like where the fish are, but the gas is not available way down low where the plants need it most. There can be a difference of gas concentration of 10X from top of the tank to the bottom. So many times, the areas where the fish are swimming has toxic levels of CO2 but the plant beds starve, so fish suffer discomfort while plants suffer CO2 deficiency.

If you can provide a video then that would be great, because then we will be able to see the whole picture and we may be able to point out some things that you might not have otherwise though of.

Also, when you have CO2 issues, a good thing to do is to lower the temperature a few degrees which will help the gas to dissolve better and then the injection rate can be reduced.

Cheers,


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## parotet

Hi Hudsonpd, have a look at the readings and figures I made at the beginning of the thread... You need to devote time and you need to be close to your tank to measure the pH every hour, but it is worth it. The best part is that you understand quite well what is happening and why you need to make the changes. The readings helped me to make some decisions on my own, instead of 'following a recipe': to switch on the CO2 earlier, to increase bubble rate, to change completely the outflow system of the tank... Each action was the consequence of a reading.

The problem is that this never stops, I guess... Now my 'worry' is that there is a bit of surface film in my tank. Still poor CO2 availability, too much organic waste produced by a significant growth of plants these weeks, brown diatoms growing on the redmoor... or probably all this together, who knows? But at least this kind of approach to your tank setup gives you a better overview of the problems you may have solved and the ones you still have to face. 

And you know what? It is fun. I love to be 'worried' for such things! Don't we keep planted tanks for that? 

Looking forward to watching your video... I also want to check if the movement of my plants is good enough. Regarding the outflow, if it is a spraybar, there is a video anywhere here where you can check what you need to have a good flow.

Cheers,
Jordi


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## hudsonpd

Thanks guys. I am pretty sure this is an issue with the diffuser (probably linked to poor maintenance), so last night I installed a new, better inline diffuser which made a huge visual difference - the mist was very fine compared to the other one and less seemed to immediately escape at the top. This is visual only, so I will take PH measurements over the weekend, as suggested to analyse the impact. I think this may save CO2 as well.

I still have the option of increasing flow some more if I need (the filter isn't currently at full power as it was very extreme for the fish) and the trick with the temperature that ceg suggested.

Fingers crossed, but I think diffuser will make a big difference.

Thanks again. I will post back the ph results over the wkd too.

Paul


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## hudsonpd

Ok, so I took readings yesterday, although I am only using a standard, test tube-type test, so I'm afraid my readings are all quite difficult to get.

Tank water left out over night was about 7.8
At 11 am (as gas goes on) it was about 7.1-7.3
By lights on at 1pm it was about 6.4-6.5 I'd say.

It then stayed pretty much stable at that all the way through to gas off and then light off - which was 3 hours after the gas went off.

Today, I put the gas on 3 hours before the lights, but I don't think the readings were that much different tbh, which is disappointing. However, it is very hard to get accurate readings with such a test kit! I don't really want to invest in a digital one, just for this at the moment.

Thoughts?


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## parotet

Nearly 1.5 drop by lights on looks fine, moreover it is stable during the light period. Further improvement could be done regarding flow to make sure the dissolved co2 gets to all the plants... you have to see them moving gently
But probably you have already done it


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## parotet

Hi everyone, a new update and a short summary of this thread (71 posts! too much reading!):

I got myself this week a CO2 atomizer... and I guess this was definitely the way to go. For the first time I have managed to have significant pH drop before lights on (despite my unknown, but probably very high water hardness... see tap water values above), around 1 point. But much better than this, the pH readings were very stable during the light period and shrimps seem happy with this new situation.

The path followed in this CO2 fine-tuning has been : glass lily pipes and ceramic diffuser in the opposite side > glass lily pipes and ceramic diffuser under the inflow > ceramic diffuser under the inflow and DIY spraybar > atomizer and DIY spraybar
During these changes I increased the bubble rate from 1 to 2 bps.

As a result of all these changes I got more and more significant pH drops, I improved the flow (really ALL the plants in the tank moving), I had a better distribution of the CO2 (atomizer magic mist) and... I hope this will lead my tank to a healthy grow!

At least today I can enjoy my first pearling...


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## ceg4048

Sounds good mate. This should improve things.

Cheers,


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## Samjpikey

Sacha said:


> Reading pH of the tank water is NOT an accurate way to measure Co2.
> 
> I have only been on this forum a couple of days, but have seen loads of people talking about their co2 concentration in terms of a pH drop- how much the Co2 drops their pH.
> 
> A drop checker is the most accurate way to measure co2 concentration. pH of tank water is affected by so many other things than Carbonic acid. Humic acids, ammonia (which is acidic), nitric acids, even some algaes, all can influence the pH. Therefore we need to read something which is constant and ONLY influenced by the co2 gas (and the resultant carbonic acid). The way we do that is with a contained amount of water of a known KH, which is not in contact with anything else that may alter its pH.






Still agreeing with this then ????  


Sent from my mobile telecommunications device


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## Sacha

We have established that measuring pH and KH can not give you an accurate reading of Co2 in PPM.

Measuring pH throughout the day can show you the TREND in Co2 dissolution. But it does not allow you to calculate PPM.

A drop checker is still the best way of seeing if you have too much/ not enough Co2. The pH only tells you what your Co2 is now, relative to what it was earlier, as in- is it higher or lower.


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## Samjpikey

Surely we only really need to know what the co2 saturation is from co2 on to lights on as this is the most crucial part and by measuring ph at these points can deliver a better indication of co2 measure then a drop checker located in only one place ?? 


Sent from my mobile telecommunications device


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## parotet

Hi all, well I thought this was finished but it is not. New variables in the equation, new difficulties to overcome...

I have now in the tank some shrimps (Amano and local crystal) and 3 Otos, so new variables to deal with. Some days ago I noticed that my "fine-tuned CO2" was not that good for them. You know what I mean: clumsy movement for fish and shrimps unusually still. When I noticed this behaviour I raised the spraybar to break the surface (bubbles), the DC turned blue in 2 hours and in half an hour everyone seemed happy again.

So, now that I had improved the CO2 solution (atomizer), flow (less filter media and spraybar), CO2 and light timings... and I had managed to have significant pH drops and healthy growing, I found that the CO2 level is not suitable for the new inhabitants.

First question: do they get used to these levels of CO2 or will I kill them slowly?

Then, I guess I have 2 options:

- to decrease the bubble rate: that is what I have done for the moment, but I fear it will damage the plants and my DC when lights on is not lime green but just greenish

- to combine high O2 and high CO2 levels. The spraybar is just on the water line creating some ripples. I have read that some people even break the water surface to have more O2 and to be able to maintain high CO2 levels (in my case, this would mean to keep on working with the previous bubble rate). I guess the DC will turn blue at night (instead of being greenish) but I will be able to have a lime green when lights on thanks to a higher bubble rate. In that case, should I have a nice rippling or break the water surface (bubbles, jets breaking the surface)? I think "Amano followers" do this at night, raising the Lily pipes at night, but changing everyday the spraybar is not a good solution for me... I have also noticed that when I break the water surface the surface film disappears, but I am not sure if this system will degass to much the water column.

Thank you for your feedback in advance.

Cheers,
Jordi


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## jose_j

Hi Jordi, 

I would go for option two, or even for a third option that consists in doing no changes in your tank. I have several Amano shimps, hundreds of Red Cherries and a couple of Ottos with high CO2 injection regime and they all are OK. I also had a shimp tank with DIY CO2 where DC was always bright yellow and shrmps population increased with no problems. 

This is just my experience, there are not two identical planted tanks, but hope it will help you

Cheers, 

Jose

Enviado desde mi ST25i usando Tapatalk 2


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## Rob P

Jordi, I run with high surface agitation and as a result pump more gas in, but this is how my fauna like it. It's weird that less gas + less surface movement V. more gas + more surface agitation has that much difference, but it did for me 

I'm not breaking the surface with the spray bar but have strong turbulance visible. Just make sure when doing water changes etc that you keep the level stable. I once filled to a cm difference over usual, thus reducing surface movement from what it was, and saw negative results on fauna. So i'm ultra careful now, also keep my filter cleaned every 2 weeks to ensure the throughput of the unit remains consistent and doesn't tail off 

The beauty of this is that once the lights and gas are off the water will oxygenate quicker (thus your DC will return to blue by AM). I hope i'm right in saying that, or that was my observations anyway!


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