I recently setup a 20g Long on my desk here at the office, I'm running a 20-30g rated power filter (non bio wheel) and an undergravel filter. Someone in the office who I doubt knows what he's talking about says that running both filters cancel each other out. Is this true? I had read a couple of times that running both can be benefical. I don't really need to run both but I had them both on hand so I used them. Just wanted to make sure it a good thing and not a bad one.
Rednek
Rednek