Join Date: Feb 2003
Location: College Station, TX
For the record, to make a gravel vac-type reactor (like the one I bought) diffuse the CO2 better, remove and squeeze the bottom sponge in the large tube while holding it underwater to allow it to soak up water. Then replace it in the reactor. This will saturate the sponge and keep it from acting as almost a total barrier to water flow through it. After all, you want water to flow through it as the powerhead pushes it down, but you want the bubbles to stay above it and get smaller and smaller as they spin around. If the sponge hasn't soaked up water (it won't really do it on its own, even if it's being held underwater--it has to be squeezed and released), a ton of bubbles will show up as the water swirls instead of the few bubbles of pure CO2 that are dissolving.
Fightin' Texas Aggie Class of 2004
37 gallon AGA Black Seal, Emperor 400, Ebo Jager 200 W, 100% Flourite Substrate, 2x55 Watt AH Supply PC Lighting (5300K & 6400K) @ ~3.4 WPG, High-Pressure CO2.