Hi. I'm getting Co2 problems on my 70Gal aquarium. Lighting is arround 40-45mmol, but plants keep melting despite my fish are Co2 stressed and keep getting BGA; aquarium is on EI. I'm guessing that the problem can be in my reactor design; let me explain: Pump is inside the aquarium (about 2500lt/h). Water goes through 1/2" tube and gets in the reactor (3" pvc tube, filled with bioballs. One hole to co2 inlet in the bottom, one hole in the top to drain gas build up as tom's venturi design suggests) On the bottom of the reactor a 1/2" pvc tube connects it to the bottom of a 6" tube that acts as canister filter. Water goes up as passes through filter media and finally returns to the aquarium. The point is that filter is always full of co2, can that have negative effects on bacteria? Can it increase the o2 demand which gives me a mistaken view of co2 levels? Will it be wise to run everything the other way arround, i mean, first filtering media then co2 reactor? I appreciate your help.