[Pauliukas]

Hello all, this is my first post in this forum. I am new here and would like to a part of you

So my question is abou PH KH and co2 table.

In the morning after 12 hours of aeration and no co2 i am testink PH KH levels in the tank before the lights and co2 turns on.

The PH is 6,5 and KH is 2

I use 50/50 - RO/TAP water, and when i check the CO2 table it shows that i have optimal co2 level ~ 30.

Does that means that i dont have to inject my presurised co2 to tank, because i have enought co2?

 

[aclaar877]

Welcome to the forum! If you have pH of 6.5 and KH of 2 then I read about 19 ppm CO2.

But, the pH/KH table isn't the best way to determine CO2, due to margin of error in testing for both as well as other things like driftwood that can also lower CO2. Many people use drop checkers, or you can do a de-gas test where you let a sample of tank water sit for a day or two, test that pH, then compare to pH when you are injecting CO2. Ideally you want at least a 1.0 point drop. Since you aerate at night, that would work the same as a de-gas test, and you want that 1.0 pH drop to take place before your lights come on so CO2 is fully available to plants when they start photosynthesizing. IYou'll have to inject CO2 to achieve 30 ppm.

 

[Pauliukas]

so that means that my CO2 has to star 1 hour before the light goes on?

 

[aclaar877]

That's what many people do - one hour prior to lights is a good starting point.

 

[johnpfaff]

When I used a drop checker, it was greenish yellow in different places in my tank. I have driftwood, aquasoil, use EI fertz. The famous chart tells me I have 95 ppm CO2. However, my fish are all fine, go figure.

John.

 

[mattinmd]

Don't use the charts to try to determine CO2 levels based on your tank water pH and KH. Those charts work if the only buffers in the water are carbonates/bicarbonates.

For some of us, this works fine, but others.. not so much. Unless you are sure how your water is buffered, don't do it.

This is also why you shouldn't use tank/tap water in a drop checker.

 

[klibs]

Don't use the charts to try to determine CO2 levels based on your tank water pH and KH. Those charts work if the only buffers in the water are carbonates/bicarbonates.

For some of us, this works fine, but others.. not so much. Unless you are sure how your water is buffered, don't do it.

This is also why you shouldn't use tank/tap water in a drop checker.

+1

IMO the best way to get the most out of CO2 is turn it up slowly until you notice that it's too much for the fish. Then you know about how many BPS to run.

 

[jrill]

I agree above for the most part. The charts get us close enough for what we do. I aim for a one point drop in pH to be close enough. Like 7.9 to 6.9 in my 10 gal. High light. Works for me.

 

[mattinmd]

Jrill, they will get you close, even very close, if you have the right water chemistry. Add a phosphate buffer like seachem neutral regulator and all bets are off. Some municipal supplies use phosphates too.

 

[jrill]

Jrill, they will get you close, even very close, if you have the right water chemistry. Add a phosphate buffer like seachem neutral regulator and all bets are off. Some municipal supplies use phosphates too.

I don't disagree, I'm just saying that for most folks you'll do just fine with charts etc. Most but not all.

 

[mattinmd]

+1. Most are carbonate based with little else. But when you start computing 95ppm and your fish are fine, you are not most people

 

[Pauliukas]

I simply increased today co2 and after 6 hours mirracle apeard, Hemianthus callitrishoides, ricia ant other plants started releasing bubbles Thank you guys .
Know i am on the project to sent my co2 difuser to recycle bin and buy a new one. in line.

Do somebody knows where is better to place in line co2 difuser: on the hose that takes water from tank, or on the hose which releases water from filter to tank?

 

[mattinmd]

From what I have read - After the filter. Injecting before the filter is asking for bubbles to form in the canister, making it noisy.