Kym, Your Biotodoma cupido requires soft water. I would recommend you keep them pH6.0 -6.5. I'm not sure of keeping them at pH5.5 but I certainly would not have them in hard water. Helen -----Original Message----- From: K & D martin <martndk@ibm.net> >speaking of biotodoma, i am reading conflicting info. >keep them with my m. altispinosas or in a harder tank. >kym ------------------------------------------------------------------------- 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"!