new to hobby filter conversion?

[justinl]

Im part of the no sump club. A sump is good because it hides the equipment and adds a volume of water to the system; this means a more stable system due to diffusion. A sump is good, but it isn't a sin not to have one. you should be stocking slowly anyways, but also keep in mind that you have only whatever water volume is held in the display; stock to an appropriate bioload.

I don't see why you couldn't use a canister filter full of LR rubble. rinse it out once every few months though so it doesn't become a detritus trap. Probably doesn't do much for getting rid of nitrates, but I would say it is very effective as a substrate for nitrosomas and nitrobacter bacteria colonization (ammonia to nitrite to nitrate). I could see it being more effective than the display's rock in this manner because the rubble has a much higher exposed surface area than large rocks.