Typically you start dosing CO2
around 2.5wpg. Anything higher and you will have algae issues, almost guaranteed.
What type of light do you have and what size tank? What plants are you trying to grow?
You will not want to run an air pump while dosing CO2
. That will off gas the CO2
by agitating the surface. HOB
filters cause significant surface agitation which can off gas all the CO2
you dose. I keep my tanks topped off that have CO2