Planted Tank Enthusiast
Join Date: Sep 2010
Location: Southern California (LA)
You can, but its not really advisable. The main worry here is driving the O2 levels far too low for your fish. It would probably be better to work with one or the other. Otherwise be prepared to be meticulous with your use and very observant with the fish and how they behave.
Don't forget to leave the lights on after dosing Excel!