Hi, I use sponge-filters in all my apisto tanks, because homemade ones are so cheap and easy. I have undergravel for some of my killies, and in a showtank in my dining room. I've run the latter for 7 years now, with excellent plant growth, and no die offs. It's the most stable tank I have ever owned. I'll jinx myself by saying this, but I have never treated any disease in that tank, and every fish death in it has involved aged specimens. It is an almost mystical tank to me - I wish I knew what was right with it. However, I can say the UG filter can't be wrong with it. I tend towards the idea a UG with a powerhead like this one works better than air driven versions though. It isn't an apisto tank per se - it's a cardinal tank, with corydoras, mixer tetras I've picked from shipments and odds and ends apistos, mismatched fish, extra males, etc. Oh yes, I vacuum the gravel every two months or so. Gary ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!