At Target pH, but more CO2 needed for Plants, what now?

[RodneyR]

Hi All--New to the forum--

Despite a few decades in the hobby, this is my first fully planted tank with medium/high light and CO2 injection, so I have LOTS to learn--

I set up a 40 gallon breeder about three weeks ago. Planted it 10 days ago. I have CO2 injection with a pH controller. No fish yet, but the plan is to keep wild caught Betta sp. so a pH around 6 would be fine. My source water is pH 6.5 and even when I set the pH controller to add CO2 until the pH hits 5.5 my drop checker shows that I am below the ideal CO2 level for plant growth. Although the Bettas would be fine at pH 5.5, I would like to add a few species that might be happier at pH 6.0, and in any case, the drop checker (brand new with fresh indicator fluid) is indicating I am not getting enough CO2 into the tank even if I drop pH to 5.5.

I am not sure what adjustments I need to make in order to add sufficient CO2 for the plantsand keep the pH from dropping below 5.5. Ideally I would prefer to maintain it around 6 during the day.

Thanks for any suggestions!
R

 

[jake72]

ph drop from co2 does not impact fish since it does not change the water chemistry; so you should not depend on co2 ph drop to reach your desired (or required ph); rather you should use some other method such as peat or decaying leaves to lower the ph to that required by fish and then control the co2 ph drop to ensure sufficient oxygen for fishes.