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

[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).

 

[dw1305]

Hi all,

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

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

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.

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

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

 

[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.

 

[parotet]

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)

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

 

[dw1305]

Hi all,

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

 

[Sacha]

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

 

[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.

 

[dw1305]

Hi all

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

 

[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.

 

[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

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!

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 😉

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!

 

[dw1305]

Hi all,

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

 

[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]

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.

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?

 

[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

 

[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 ?

 

[Samjpikey]

Are you using a spray bar or lily pipe ??


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[parotet]

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 😡

 

[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]

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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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!