Planted Tank Guru
Join Date: Dec 2012
Location: Hot Springs Ar. 71901
"High" O2 would usually involve disturbing the water quite a bit. With two HOB filters
you should have a "normal" amount of O2. So why do you want it to be higher than needed for fish to live ?
Plants take in CO2 and generate O2 as their waste product, the reverse of animals.
This comes to a stop after lights out because the growth process has stopped.
So you should stop the CO2 at dark or even just a bit before that.
The water in the tank contains a normal amount of CO2, but the plants do use it
while the light is on. So if your adding more of it and the plants no longer use it after lights out, then it will build up if you keep it running. That is what might hurt the fish.
But as long as you turn it off, it will slowly return to that normal level of it that you already have if none is being added.
Not that familiar/w the other plants but the Petchii(?) look to be less than a year old and in good health.
The Amazon looks great. I think I'd take a look at the ferts if you aren't getting the growth you expect.
The shortest distance between any two points is a straight line...in the opposite direction...
Last edited by Raymond S.; 06-24-2015 at 08:15 PM.
Reason: more info...