# Reliability of Drop Checkers



## skeletonw00t (9 Jan 2012)

I'm sure they don't mean much...

Mines always yellow & I dose EI yet I still get algae and slow growth.

Something can't be right there - I also have like 20x turnover in my tank.


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## sussex_cichlids (9 Jan 2012)

all depends what water your using in it 

I learnt bit about these other day 

I was using tank water in mine till other day when i found out that's not very accurate best stuff you can use in 4dkh water which you can make yourself using ro water and bicarb soda or you can by a premix bottle of 4dkh water that would give very accurate readings


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## GillesF (9 Jan 2012)

skeletonw00t said:
			
		

> I'm sure they don't mean much...
> 
> Mines always yellow & I dose EI yet I still get algae and slow growth.
> 
> Something can't be right there - I also have like 20x turnover in my tank.



How much lighting do you have?


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## spyder (9 Jan 2012)

GillesF said:
			
		

> skeletonw00t said:
> 
> 
> 
> ...



Within here lies the answer.


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## GillesF (9 Jan 2012)

skeletonw00t said:
			
		

> I'm sure they don't mean much...
> 
> Mines always yellow & I dose EI yet I still get algae and slow growth.
> 
> Something can't be right there - I also have like 20x turnover in my tank.



How much lighting do you have?
And the dimensions of your tank?


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## skeletonw00t (9 Jan 2012)

I have 2x T8 tubes - 25 watt each, my tank is a 130litre...

I know it's not a light issue though - as I am still getting Algae - which, if anything means too much much light & not enough CO2.


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## sussex_cichlids (9 Jan 2012)

What ferts you using and how much you dosing?

What filter you got whats it flow rate?

How often do you do water change and how much do you changing?

What you Photoperiod on the lights?


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## skeletonw00t (9 Jan 2012)

Dosing full ie daily. I recently posted on the ei tutorial with what i dose (sorry i am on my iphone).

Photoperiod is 7 hours

40% changes bi weekly


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## skeletonw00t (9 Jan 2012)

Oh and filter rate is 1500 ltr hr & i have 950ltr/hr korAlia in there too :/


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## Ian Holdich (9 Jan 2012)

you need to up the water changes Woot. You have exactly the same lighting and set up as me. I don't get fast growth (which is quite nice after having a tank where that plants went mental). A 50% weekly will make a difference.


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## sussex_cichlids (9 Jan 2012)

everything sounds about right 

if your using EI method 

Like Ianho said above try 50% weekly water change also cleaning any visible bits of algae of rocks and leaves and glass etc

You should see an improvment after few weeks


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## skeletonw00t (9 Jan 2012)

I'm doing two 40% water changes weekly :/


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## GillesF (9 Jan 2012)

skeletonw00t said:
			
		

> I have 2x T8 tubes - 25 watt each, my tank is a 130litre...
> 
> I know it's not a light issue though - as I am still getting Algae - which, if anything means too much much light & not enough CO2.



What kind of algae?


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## skeletonw00t (9 Jan 2012)

Black beard & the brown stuff


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## sussex_cichlids (9 Jan 2012)

yea that can still cause your problem you could be removing to much ferts during your water change that would then make the co2 your dosing unusable to the plants and that's whats feeding your algae 2x 40% might be to much try doing 1x 50% or 2x 20% a week see if that makes a difference  

80% a week is a bit excessive 

from everything you put it all sounds about right this last thing i can think of


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## foxfish (10 Jan 2012)

So your problem is that your DC shows yellow but you have algae issues?
As has been mentioned - unless you fill the DC with 4dkh water (available from the sponsors) your checker wont tell you anything you want to know!


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## skeletonw00t (10 Jan 2012)

My DC does use 4dkh - ita from aqua essentials.

I am replacing ferts after the water change :/


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## ceg4048 (10 Jan 2012)

Hi skeleton,
                There are a couple of nuances here that you need to think about. BBA is the trickiest of all the algae types because it cannot be pummeled into submission. ferts have nothing to do with BBA so EI is completely irrelevant in this case and I see no reason whatsoever to adjust your dosing or to adjust your water changes. the bigger the water change the better. There is absolutely no such thing as too much water change....EVER...

Ordinarily, most CO2 related algae, like hair algae, can be beaten by simply adding more CO2, but BBA occurs due to instability of your CO2. This typically means that when the plants need lots of CO2 there is not a lot of it around and when they don't need a lot of CO2 there is lots of CO2 around.

So one of the ways to beat BBA is to carefully manage the timing of your CO2 application, so that when plants need a lot they get a lot and when they don't need a lot they don't get a lot. So first of all you need to understand, in that particular tank, just exactly how the CO2 is behaving. We need to know just exactly when there is a lot and when there is not a lot of CO2 in the tank. The only way to get a clue is to take direct pH readings of the tank water at various points in the day. A pH reading every hour, or better yet, every half hour from 2 hours prior to lights on until lights off. The dropchecker is too slow to be useful in this exercise and a pH meter is a handy tool to have.

Generally the CO2 profile in the tank should be something like this:
2 hours prior to lights on - pH at it's maximum daily value => Turn gas ON.
1 hour prior to lights on - ph drops 0.5 units below maximum daily value.
Lights on - pH is at it's lowest daily value, approximately 1 unit below maximum daily value.
1 hour after lights on - pH is slightly above lowest daily value.

The above is an ideal scenario but it's very difficult to achieve. Often, if you are able to drive the CO2 to nearly it's maximum value (pH near it's minimum value) by lights on, the injection rate will continue to drive the pH downwards so that the fish begin to suffer. Maximum CO2 (which causes minimum pH) is required at lights on. A few hours prior to lights OFF, the plants start to drop offline and they do not need as much CO2. Many tanks have trouble in that they do not reach their maximum CO2 until several hours after lights on, and this causes problems, both for plants and fish.

Apart from your CO2 timing you also need to review the distribution of your flow to ensure that you have an even and strong flow across the entire tank. It may help to daily dose liquid carbon products in the mornings to help with the CO2 availability at that time.

By the time you fix the BBA the diatoms will also have been fixed.

Cheers,


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## skeletonw00t (10 Jan 2012)

Thanks Ceg, great response as usual!

The problem i have is that my CO2 is on 24/7 an the DC is always yellow. Its by DiY FE through an inline difuser. So really there shouldnt be an issue with stability?

Am i right in thinking that bba algae will not just go away on its own even if conditions are right? And that more co2 could actually help it grow? Anyway i've ordered some liquid carbon to try to nuke it. 

Just really don't know why i am not getting strong plant growth even with my high amounts of co2. 

I am sure its because the bubbles are too big through the boyu diffuser - but the bubbles in the water are enough to trigger the DC to turn yellow - if this makes sense?

Tom


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## ceg4048 (10 Jan 2012)

Well, like all algae, BBA love CO2 just as much as plants do. But having CO2 24/7 means nothing if the output of your CO2 device is unstable, which DIY CO2 techniques usually tend to be. You still need to look at the concentration profile of the tank as a function of time in order to give you a clue of when the CO2 is at it's highest, medium and lowest levels.

The problem is not that BBA love CO2, but that that BBA do not care about whether the CO2 is stable or not, while plants do care and suffer if it is not stable. BBA in a way can sense whether or not the plants are responding well to the CO2 profile. Think of BBA and any algae in the same way that you think of predators such as lions or wolves. If the prey is healthy then the predator will not attack, but if they can determine that the prey is weakened and vulnerable then they attack immediately.

You are correct n that BBA tends not to go away even if you improve conditions so you need to evict it from the tank, normally with liquid carbon and/or a lot of elbow grease, however, if you have not improved CO2 stability, then it will return with a vengeance.

You need to look at the CO2 profile by taking the pH measurements first and foremost. You might discover something you were unaware of.

Cheers,


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## skeletonw00t (10 Jan 2012)

Ok so first thing is to get a ph tester? Where is the best place to get one of these?


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## sussex_cichlids (11 Jan 2012)

skeletonw00t said:
			
		

> Ok so first thing is to get a ph tester? Where is the best place to get one of these?



There's two type you can consider 

Traditional Chemical Test Kit 
Nutrafin Ph Wide Test Kit £7.99 From http://www.aquaessentials.co.uk 



 

Digital Pen Type (What i use  cannot say anything bad about it must remember you will need calibration fluids to check it once in while) 
ph-009-ia pen type ph meter digital tester hydro £7.33 From http://www.mystore365.com 
View attachment 134804


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## niru (11 Jan 2012)

Hi Clive!




			
				ceg4048 said:
			
		

> Well, like all algae, BBA love CO2 just as much as plants do. But having CO2 24/7 means nothing if the output of your CO2 device is unstable, which DIY CO2 techniques usually tend to be. You still need to look at the concentration profile of the tank as a function of time in order to give you a clue of when the CO2 is at it's highest, medium and lowest levels.
> 
> The problem is not that BBA love CO2, but that that BBA do not care about whether the CO2 is stable or not, while plants do care and suffer if it is not stable. BBA in a way can sense whether or not the plants are responding well to the CO2 profile. Think of BBA and any algae in the same way that you think of predators such as lions or wolves. If the prey is healthy then the predator will not attack, but if they can determine that the prey is weakened and vulnerable then they attack immediately.
> 
> ...



does this means that once the tank conditions have been improved and stabilized, then manually removing all the BBA muck is the only way forward? Even if it means destroying your garden, and then perhaps re-planting it later with newer plants? No austerity measures possible in this tough cost cutting and Euro-problems environment?


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## ceg4048 (11 Jan 2012)

Yeah mate, that's one of the annoying features of this type of algae. I mean, with species like BGA, often if you catch it early, you can just throw NO3 at it (The Holy Hand Grenade of Antioch) and it will run away. But BBA just sits there and stares back at you, so it's very hard to tell at what point you have actually achieved the right set of conditions in terms of CO2 stability. Before the popularity of gluteraldehyde type products, we were forced to meticulously pick and clean and harass the tufts for a long time. H. peroxide dips/spot treatment were also used. Nowadays, one can simply carpet bomb the tank with Excel until the tufts turn pink/purple, and if it doesn't grow back then you know you have it right. So you really never need to disrupt the scape unless you have sensitive inmates or if you have plants that respond negatively to carpet bombing...Austerity measures? Pfah, let Lisbon and Athens worry about that...

Cheers,


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## ceg4048 (11 Jan 2012)

skeletonw00t said:
			
		

> Ok so first thing is to get a ph tester? Where is the best place to get one of these?


Well, I mean, you already have a pH test kit, don't you? The fluid used in your dropchecker is a pH test kit unless you are using that all-in-one blue liquid. But if you are using clear 4dKH water and if you then add that orange liquid to the checker then that orange liquid is the pH reagent and you should have received a color chart with that reagent.

As much as people winge about pH, I'm amazed that there aren't more folks using a pH meter. Just have a look here=> Amazon.co.uk Hana pH meters My favorite is item 6, which is a pH/TDS/Conductivity meter. It's so easy to use and is almost instant. No messy liquids, except for when you have to calibrate, which is not that often, and no silly color charts to interpret.

Cheers,


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## skeletonw00t (13 Jan 2012)

Can't you get a cheaper ph meter? I thiught they'd be like a fiver :/


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## PeteA (13 Jan 2012)

In the UK you're looking around a tenner.  I've been wanting to get a digital one for a while - what I'd love is one that has a probe that lives in the tank and the display lives in the cupboard but I fear that is completely out of my price range


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## GillesF (13 Jan 2012)

ceg4048 said:
			
		

> skeletonw00t said:
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Hey Ceg

so if I understand correctly, you double check your DC measurements by testing the pH and comparing that value to those in the pH/KH table? So if your aquarium water has 6,6 pH and 4dKH (from your DC) that would mean 31ppm of CO2, right? In that case, the pH/KH table is reliable because the KH solution is "clean" from other sources that might influence the test (acids etc)?

How accurate is that Hanna meter of yours?


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## sussex_cichlids (13 Jan 2012)

PeteA said:
			
		

> what I'd love is one that has a probe that lives in the tank and the display lives in the cupboard but I fear that is completely out of my price range



Like this you can get these for about £100 with P&P great for using with CO2 just set the ph you want for you plants and it will dose your tank till the required pH is reached and then turn the CO2 off preventing the CO2 levels becoming to toxic this you leave on 24hrs a day and will keep a constant pH level in your tank   





Or you can get a seneye for that money but it wont control the co2 levels in fish tank but it will give you a PH reading and few others readings depending on the model you purchase the best feature i like is that it will text you when you setup your tanks parameters if any were reach a dangerous level if your at work or on holiday in japan it will alert you you can pop home or ring a mate or member of family and get it sorted before its to late think this is very smart device and got one on my shopping list


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## ceg4048 (13 Jan 2012)

GillesF said:
			
		

> Hey Ceg
> 
> so if I understand correctly, you double check your DC measurements by testing the pH and comparing that value to those in the pH/KH table? So if your aquarium water has 6,6 pH and 4dKH (from your DC) that would mean 31ppm of CO2, right? In that case, the pH/KH table is reliable because the KH solution is "clean" from other sources that might influence the test (acids etc)?
> 
> How accurate is that Hanna meter of yours?


No mate, you cannot compare the pH readings of the tank to that of the dropchecker. The tank water has unrelated organic acids that corrupt the calculations used in the tables and therefore the pH reading of tank water cannot be used in the tables, however, for this exercise, we assume that in the space of 6-8 hours, those organic acids concentrations won't change too much, so what we're looking for is the change of pH over that period, which we then assume is due to the change in the carbonic acid only, and thus will indicate a change in the CO2 content. The dropchecker water has no other acids. It is completely isolated by a column of air and so the changes that occur within the checker do reflect the absolute values of the waters CO2 content. However, because of the mechanism by which the checker works, it cannot tell us what is happening _right now_. It is always a few hours behind in it's indication, therefore we cannot use it for this exercise, because the slowness of it's response masks the behavior of the phenomenon we are trying to investigate.

In this exercise, the instantaneous pH reading of the tank is not being used for determining absolute CO2 PPM. It's only being used to track changes in PPM. Can you understand the difference? BBA is caused by unwanted changes in CO2, so we need a way to see those changes, not a way to measure absolute values. If our assumption is correct - that the tank water acids don't change appreciably in relation to the carbonic acid over that time period - then it illustrates for us a profile of how the CO2 levels change as a function of time. Understanding how the CO2 levels change, in this case, is more valuable than understanding absolute values, because this particular algal bloom is related to the rate of change of CO2.

Hope this makes sense...  

Cheers,


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## skeletonw00t (13 Jan 2012)

Ceg - am I right in thinking that me messing round with the co2 over a week (turning it up reguarly) could be causin algae issues?


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## ceg4048 (13 Jan 2012)

Hi mate,
           Normally, just a simple increase in injection rate is not a problem. In fact you should have seen an increase in growth rate and an increase in plant health if all you did was to increase the CO2 concentration levels. If you were turning it up and down and generally fiddling with it in every direction then, yes, that could always a contributing factor, but i don't think that this all happened just in the space of a week right? As i mentioned before, DIY CO2 is almost ALWAYS unstable because the rate at which the sugar is consumed and the rate at which the yeast live, die and excrete CO2 is very difficult to control. The gas pressure changes easily, from day to day and from hour to hour causing the flow rate to fluctuate. This is a textbook recipe for BBA, generally. That's why I mentioned in an earlier post to maybe supplement your CO2 with liquid carbon. If affordable, a pressurized cylinder is always preferable.

Cheers,


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## skeletonw00t (13 Jan 2012)

i am using a cynlinder and have been messing with it this week.

Don't know why but hair algae has started to appear. I brought some flourish excel so will overdose for a week to clear up my algae.


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## skeletonw00t (13 Jan 2012)

Also ive changed my diffusion method so that the co2 is being injected into the filter - so hopefully that will make sure im getting good co2 all round the tank!


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## GillesF (13 Jan 2012)

ceg4048 said:
			
		

> GillesF said:
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Yeah, makes sense.

Another question: BBA is caused by unstable CO2. But what if the CO2 levels are unstable (due to tweaking) but still optimal (e.g. staying above 30ppm). Is it still possible to have BBA then?


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## niru (13 Jan 2012)

Guys

I too have had good share of CO2 issues. But funnily other than BBA, and occasional GDA, other algae have been off limit in my tank! BBA is a real bane..

I use CO2 cylinder with 4-5 bps, 2hrs ON before and 3 hrs OFF before lights. I have a inline diffuser (Dupla Reaktor S) with 9/12 holes. So I had to adapt my cannister pipes 16/22 to fix it, resulting in pressure drop & so a CO2 distribution issue.

Got atomizer, but had major pain since the pressure needed to force the gas is way different than the reactor. Fidling around gave a very unstable and varying CO2 in the tank... got a major BBA mess, plants suffered. So now am back to the diffuser, but added another cannister for flow. All is well in last 3 weeks. But BBA isnt subsiding.

As master Ceg pointed out, one needs to simply slay away the remnant BBA and look forward..

In all this, I got JBL CO2 liquid. It claims to be a ready-2-use with 35 drops into the DC should start showing the CO2 level. Even after 5 bps, and moderate-2-heavy pearling, my DC always remains dark blue!!!! Theres no extra water added, and I have 4 bottles of this JBL liquid now. Relying too much on these chems is a definite problem.. 

-niru


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## ceg4048 (13 Jan 2012)

skeletonw00t said:
			
		

> i am using a cynlinder and have been messing with it this week.
> 
> Don't know why but hair algae has started to appear. I brought some flourish excel so will overdose for a week to clear up my algae.


OK, well any filamentous algae is definitely related to the absolute value of the CO2 so that means you were low on the injection rate when you switched over. Remember that overdosing only works short term for any of these. When you stop overdosing the injection rate needs to be high enough, the diffusion method needs to be sound enough, and the flow rate and distribution method from the outlet pipes needs to be correct enough in order to keep the plants healthy enough to resist and suppress the blooms.

I assume that you also have a solenoid and can now shut the gas off? If not, and if you are still using it 24/7 then you can easily maintain good stable levels. It's always a good idea to reduce the light intensity while messing around and trying to find the CO2 sweet spot.

Cheers,


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## ceg4048 (13 Jan 2012)

GillesF said:
			
		

> ...Another question: BBA is caused by unstable CO2. But what if the CO2 levels are unstable (due to tweaking) but still optimal (e.g. staying above 30ppm). Is it still possible to have BBA then?


Yes, you can. Barr describes CO2 as a narcotic. Plants get hooked on high levels, so when the levels change in a downward direction they start failing even if the absolute value of the new lower level is still what we refer to as "optimal". Take a deep breath, buckle you seat belt and check out the discussions in What causes green spot algae,hair algae and some causes.... and Co2 Fluctuations and BBA and see if any of that makes sense.

Cheers,


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## Aquadream (13 Jan 2012)

My observation is that relying on CO2 drop checker readings is one good cause of algae.
Let me explain.
CO2 drop checkers are too slow in their colour development. By the time the drop checker changes colour the CO2 levels could be way out of line.
As well explained by Ceg4048 plants react with rapid changes of enzyme production to the changes of CO2 levels.
CO2 checkers can not follow those changes in any way before some damage is done.

I have stopped using drop checkers.

Instead I use electronic PH probe and monitor the PH in let say 3 points of time during the light cycle.
I do that during the start up period of a new set up and periodically when the set up is well developed to make sure that everything goes smooth.
When the lights come on, mid cycle and when the CO2 goes off. The CO2 in my tanks always goes off an hour or two before the lights depending on the tank size and particular set up conditions.
On the other hand I would program the CO2 on time as early as 5 hours (depending on the set up) before the lights to make sure that the CO2 level is good when the lights come on and that there is stable CO2 level with as little as possible change during the light cycle.
After that it all comes down to stable supply of CO2 in the tank, good quality valves and relatively stable ambient temperature of the room where the tank is placed as the changes in ambient temperature could influence the CO2 supply rate.

I found CO2 inline reactors to be the best for maintaining stable CO2 levels, because they can not change suddenly the CO2 levels as glass diffusers and atomisers can.


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## hotweldfire (13 Feb 2012)

Man, I have been looking for this thread for a bit and, bang, skeletonwoot creates it for me. Thanks mate.

And Clive I have been looking for this specific post:


			
				ceg4048 said:
			
		

> So one of the ways to beat BBA is to carefully manage the timing of your CO2 application, so that when plants need a lot they get a lot and when they don't need a lot they don't get a lot. So first of all you need to understand, in that particular tank, just exactly how the CO2 is behaving. We need to know just exactly when there is a lot and when there is not a lot of CO2 in the tank. The only way to get a clue is to take direct pH readings of the tank water at various points in the day. A pH reading every hour, or better yet, every half hour from 2 hours prior to lights on until lights off. The dropchecker is too slow to be useful in this exercise and a pH meter is a handy tool to have.
> 
> Generally the CO2 profile in the tank should be something like this:
> 2 hours prior to lights on - pH at it's maximum daily value => Turn gas ON.
> ...



Here are my readings from my main tank yesterday using a PH pen:

9:30 - 7
10:00 - 7
10:30 - 6.8
11:00 - 6.7
11:30 - 6.6
12:00 - 6.5
12:30 - 6.5
13:00 - 6.4
13:30 - 6.4
14:00 - 6.3
14:30 - 6.3
15:00 - 6.3
15:30 - 6.3
16:00 - 6.3
16:30 - 6.3

at which point I stopped checking. However, checked tonight at about 7pm and it was 6.3.

Here's the thing though. 

CO2 comes on at *9:30*. 

Lights come on at *13:00*.

That's right, three and a half hours prior to lights on.

PH drops 0.5 below maximum daily value 3 hours after co2 comes on and doesn't reach its lowest level until 14:00 which is one hour after lights on and *five and a half hours after co2 comes on.* 

What the hell is that about?

Is it just the injection rate is too low? I know one shouldn't rely on pearling but I get pearling about one hour after lights on (but who knows it might be the hair algae in the Elatine hydropiper, not the actual hydropiper  ). Drop checker is lime green by 15:00 mind.


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## ceg4048 (14 Feb 2012)

Hiya mate,
                 Sorry, I had to re-read the whole thread again. Can you confirm  that you have hair and not BBA? I get confused sometimes when the thread is idle.

In any case, yeah, my knee-jerk reaction, if this hair, is to suspect an injection rate issue because it's taking 3 hours to drop the pH significantly, however, pearling 1 hour after lights on usually means that you are bang on, so there is some inconsistency.

You're absolutely certain that flow and distribution are good? If so then an increase in rate and a gas on time a little less than 3.5 hours should do the trick. Why does it take the DC till 1500 to go lime green at 6.3? That's also suspicious, so watch your critters and inch the injection rate up carefully, especially if you've got shrimp or other vermin in there.

Cheers,


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## hotweldfire (14 Feb 2012)

Yep flow and diffusion good. Use inline reactor which is dangerously efficient. Used to get BBA until I introduced a second Koralia then it went within a week. 

Now get filamentous and cladophora. The former at least was under control until shrimp wipe out courtesy of Plantedtanks insecticides. Now getting worrying. 

Will try upping the rate very gradually.

Sent from my MB860 using Tapatalk


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## AverageWhiteBloke (31 Dec 2012)

Really good post, I know it's been dead a while but I'm glad I came across it. Taught me more about co2 profiles than any other. Next step for me checking my own co2 arrangement 
I have a co2 bottle just about to run out so I think I'll try and do more work in getting it right. Relied to heavily on the DC up to now. I don't have any major BBA issues just selected areas on hardscape which I spot dose with LC. The BBA growth rate is matched by the spot dosing so never really gets a good hold.


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## Eugine Thomas (20 Feb 2015)

I don't understand: you shouldn't be starting out by aiming for a given level of carbon dioxide; instead, start by slowly adding carbon dioxide, day-by-day and week-by-week; if the plants don't gradually improve then there's something's wrong and you need to work out what's wrong first; if they do improve in their general health, and they look good, then stop and stabalise the tank. To be honest: drop-checkers are little more than canaries down the mine.


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