Hey everyone, So I have been doing this for a while now and was wondering if anyone else does anything like this to a spare HOB filter they might have laying around. I run an Aquaclear 110 as the main source of filtration on my 55 gallon but I also have this spare whisper 60. I thought this would be a good idea for extra Biological and mechanical filtration along with a sponge filter inside the tank. Has anyone else done this or does anyone else have custom sump type things they do with there HOB?