Best Filter/Placement

From what I've heard, the filter you have is fine. I just recently bought the same filter for my oldest tank and I'm waiting for it to arrive.
I'm interested to hear the opinions on placement of the filter.
I've been thinking of moving my internal filter from the back left side of the tank to the left side, so that the water flow moves longways across the tank.(from left to right) In my newest 10g.

An aquaclear will work just fine. Just keep the water level relatively high so it minimizes the splashing. How are you injecting co2? Into the intake? If so, that will work just fine and the rectangle spong will actually serve as a diffuser for you (co2 will get trapped in the small holes). If you're using diffusion, there shouldn't be much loss either. Its a good cheap alternative to a canister filter.

A future option if you want to go towards a canister would be an Eheim 2213 for a 20-29g tank. I'm sure others will recommend an XP1.

thanks for the reply, do you think running two aquaclear 50's on my 20 gallon would be overkill? i am using the hagen DIY CO2. i just want to make my water crystal clear and keep my plants/fish as healthy as possible. :icon_wink

I placed a AC50 in the middle with fairly high water level and it seemed to really work well..