I run CO2 24/7.
It is connected to a meter that controlls the ph. Keep it at arround 6.5.
Plenty of bubbles from the plants.
GH is 0, kh at 4.5, stable. Tapwater the same.
When the CO2 bottle is empty (and I'm not home, realizing it), Ph has risen to 7.6. but tapwater is at 7.0. Do weekly 10% change.
I don't understand why it goes that high, anyone has a explanation?