I have a 29 gallon with an AquaClear 50. I have an unopened, backup 50 that I keep in case the other dies, but it occurred to me today that I could add it to the other side of the tank. Then if one dies, I still have the other running. Even though I'm sure the one 50 is enough, I thought this might help the tank stay cleaner and help with added oxygen. Any downsides to running an extra filter on my tank?