EHEIM wet/dry external canister filter
- Thread starter Co2
- Start date
O2 and CO2 do not compete, both dissolve independently of each other. Many use wet/dry filters. Tom has described how he has his setup in several threads. check out his 120 gallon non CO2 thread for a picture and a description of how it works with CO2 injection.
I think eheim no longer makes these models, although I don't know why.
I think eheim no longer makes these models, although I don't know why.
I have the 2229 in parallel with a 2128 in a heavily stocked tank. Honestly, I have absolutely no idea if it makes any practical difference in the health of my fish or plants.
CO2 pushes fish to the surface because hemoglobin (the protein that binds oxygen in red blood cells) is affected by CO2 concentrations. In the body, areas with higher CO2 concentrations cause hemoglobin to release the bound oxygen it received from the lungs, or in this case, gills to the tissue and then another part of that protein binds CO2. This CO2 is brought to the lungs or gills, an area of high O2 concentration and low CO2 concentration. The CO2 is released and O2 is bound again. CO2 effects hemoglobin's affinity for O2, so in a sense they compete within the organism, but not for dissolution in the water. When CO2 is too high it inhibits hemoglobin's ability to release CO2 and then bind O2, so the fish go to an area with a higher concentration of O2 and lower CO2, the boundary of the water where gas exchange occurs.