Whenever I used UGFs, I had the airstones all of the way down. The further the bubbles travel the more water it'll move? Just my opinion. But I also agree, if you want low maintenance, go with an HOB
filter like the aquaclear. They're pretty cheap, reliable, and you don't have to tear your tank down to clean them.
With UGFs, once you start using them, you MUST continue to use them FOREVER, unless you are going to rip your tank down to remove it. If you simply stop using it, all of the stuff it has collected (look through the bottom of your tank) will decompose and release bad stuff into the tank. Also, you can't use sand as your substrate (unless you do ReverseUGF I think? correct me if I'm wrong). You also can't use rooted plants, as the roots will get down into the filter and clog all of the holes.
Also, every year or so, you DO have to rip down your tank to clean the UGF
. If you read carefully about them, you'll find this out. So if you already have it set up, it's fine, just wait until you have the money to buy a HangOnBack filter then take the UGF
out of the tank.
In all honesty though, UGFs aren't bad filters, they do their job well, just the maintenance that goes along with them isn't worth it.