Hehe...not every setup can have sump system leh...like my 4 foot tanks all old old from my dad, no space to put sump...same goes to other tanks I have. So I use sponge filters and modify the overhead filter a bit...works okay for my dad so far. But I do recommend using sump system. I use sump system for my uncle's 4'x2'x2' tank in KL...the tank loaded with full of high quality bio-rings form Germany(taken from my dad since he replaced his in his koi pond with blue jap matting...they cost a bomb though these rings) can take hell of a load. Last time my uncle put in an 8 inch Syns, three 6-7 inch bifas, 4 burundi frontosas(4-7 inch) and 2 plecs, just change water once a week, the fish all grew very fast. Only had to separate all the fish after the bifas paired off(torturing the last bifas) and the Fronts while they were not target of any agrression, the large syns and bifas pair hog all the food and the Fronts started to lag behind in growth. So to feed them properly removed them.

Note: Bifas were put into this setup at 3 inch...kept in this setup for 2 months they doubled their size to 6-7 inch.