Originally Posted by milalic
Do you think I can use the CO2 in my tank?
Florabase is a damn fine substrate, it would be sad to trade it out for anything else, it is better than EC or Flourite for growing the more demanding plants, and all other plants, unlike EC, etc. ( Although EC and Flourite are good subs)
Not sure how you were testing for alkalinity, but a kh kit may be better, Florabase will lower the hardness/kh but not to zero, Florabase is designed to make the water acidic,
I have used it while injecting C02 and keeping fish without error, yet it is challenging, due to the makeup of FB. (C02 off with lights, keeping kh 3 or above etc) I would suggest a better kit for testing kh if you are unsure, and then it would need to be used in conjuction with ( as GMOP stated) a feel, meaning, knowing what the tank is doing/needs just by looking at it, which is something that comes from experience.
However I do not keep fish it in at this time, strictly because I can't, I use 90percent RO water with C02 and a kh of 0~2 a very low ph, for the plants that demand an acidic environment to flourish.
Therefore, the water is to acidic for fish and invert's.
So I think it really depends on what you want, how long have you had the FB? and if you trade it out, what would you sell it for?