I think torf is german for peat.....my guess is that it is a cannister filter filled with peat,and the zeolite is to take out the colour. I 've heard lewis refer to it before,never bothered to ask,just assumed thats what it was. Steve Van.B.C ------------------------------------------------------------------------- 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"!