filtration

[benji-star]

i was given a dual waterfall regent filter i am not sure how many gallons or any thing like that but i saw at the lfs a attachment that will turn the filter in to bio wheels- just wondering if anyone has done this -how did it work out for you if you did-
thanks

 

[benji-star]

one other question the big space int the back of the filter should that be filled with some sort of media or should it be that just a big space.