FIrst you have to consider the amount of bacteria a UGF
can hold?? The bottom of the tank times 3 inches thick. A heck of alot more bio filtration than any thing out there except a FBF
or perhaps a trickle filter. The bacteria needs slow moving water not fast So hang on the back type filters are not the greatest for bio loads. You can use one with a bio wheel but how big is a bio wheel??
You take a UGF
and slap on a power head and vaccum once a week and youll have one of the best lowest cost filter for bio load you can find out there.
I have hanging filter and UGF
filter in all my tanks but 1 my 1.6 gallon it has a UGF
only. I have had my 29 gallon tank for over 3 years ( UGF
with 2 power heads ) and havent had a problem yet.
If you do get a UGF
get a power head dont use the old air flow method and Put 3" of gravel over the top of it. Vaccum weekly and youll have very few problems.