Yuo can use sand on a reverse-flow UGF, but I believe that the sand will get sucked through the plate on a regular UGF. Jason Miller Sherwood Park, AB Jeff Katcher wrote: > > Is sand compatible with Undergravel filters? if so I might look into > it. otherwise i will use some form of fine gravel. > > Jeff ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@majordomo.pobox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@majordomo.pobox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!