Planted Tank Obsessed
Join Date: Aug 2010
Location: Fort Collins, CO
It's not "bad" for your tank. It just reduces the amount of CO2 in the water if you are injecting it. So, the only problem is that you use more CO2 and that costs more money/time to get a refill.
That said, I have a sump, which some say is terrible for off gassing CO2, but I haven't had any problems.