Here is the story. I am putting together a 55gal tank in the house to start about 50 Tilapia and leave them in there untill they are 2-3". They may be moved out a little sooner all depends on how quick I get my 300gal tank set up in the barn. The issue is the bio-filter I been doing a lot of reading on them. The question is that I can not seem to find is, is there any advantage to a up flow verses a down flow. I have used a down flow in the past with no problems. This will be a new build so I can go either way. The only disadvantage that I can see on the up flow is you have to take all apart to clean the bottom where all the gunk will be coming in. On the old filter I had I used a course filter pads as a per filter where the water dumped on it. When they started to plug I could pull it out to clean. I am thinking that the filter will be 10-15 gallons in size. I don't think you can go to big. Looking for any input.

Thanks,
Tandy