bristle nose pleco question
A planted tank does not experience low oxygen levels at night due to CO2 levels as the two gasses do not interfere with eachother’s concentration (one does not displace the other). A tank, planted or not, should have sufficient turbulence/movement at the surface (from your filter’s return) to assure a sufficient rate of gas exchange. This is key in setting up any aquarium, HOB filters automatically cause such turbulence as they drop the water back into the tank from above the surface, however a return from a canister filter could be positioned too far below the surface to cause problems. Most tanks in such a condition also tend ot build up an organic film over the surface due to insufficient movement.
Other than that, eccess decaying matter and/or overstocked conditions tend to be the other causes of low oxygen levels.
Hope that helps Giancarlo Podio, LMD
Category: Philippines Internet Koi Society
