I just started a fishless cycle with 20g tank. Not much in it so far UGF, and a HOB 150 Bio Wheel. My ammonia is a 2.0 and temp is at 80. But now I am doing some research (better late than never??) and I am seeing that an UGF is unnecessary and could even even be harmful in the long run. It is a single unit UGF with approximately 1/4 inch ridges so there is less room to trap debris. When up and running I will vaccum when I do PWC. So, leave it or take it out now? Feedback?