db8

i see. how about cardinal tetras with the neon tetras?

bartoli

Yes, at one time I did add cardinal tetras and they mixed in well with the neon tetras - the two even schoaled together. But eventually the cardinal tetras did not last because my water pH was not low enough. At that time, my plants were growing so well that the day time pH peaked as 7.8. The cardinal tetras just couldn't take such high pH.

Right now, I am experimenting with pressurized CO2 to lower the water pH. The neon tetras like that - they are more active and have better appetite. May be one day I will re-introduce cardinal tetras.

tranr

I've been told that ADA Aquasoil also lowers pH.

bartoli

Didn't know that. Thanks! Wonder if any one had used Aquasoil for that purpose in a soil-based tank?

So far, I am happy with the outcome of using pressurized CO2 along with a CO2 controller. As expected, plant growth rate picked up a tiny bit. I did not want to have frequent pruning and I had read Ms. Walstad's potential concern about soil nutrient depletion due to the explosive growth made possible by CO2 injection. No issue with algae. Lighting remains the same as before, i.e. low light. No dosing. Most important of all, the neon tetras seem to be happier.