I think the cacatoides would love it, although they are not a blackwater fish, per se. They come from further up in the Andes where the rivers feeding into the amazon are higher in dissolved minerals and higher pH. But, I find that they are not sensitive to small variations in pH and hardness. (within reason). Depending on what other fish you have in there, they should do well. And they just _LOVE_ coconut shells. One time I put in a piece of shell, the female checked it out within 5 minutes, and an hour later they had finished spawning. It was truly amazing! Right now I have cacatoides breeding in a community tank that only has Anubias and Java moss in it. Most of the plants are attached to wood, but I have quite a number just barely in the gravel so that their roots look like a miniature mangrove swamp. The fry are swimming in and out and around the roots looking for micro-organisms to munch on. I no longer try to save them all. If each mother manages to raise 5 that's enough. I don't want to have a fishfarm. My pH is 6.6 to 6.8, I use a DI and blackwater extract. But that is mostly for the benefit of the cardinals etc. who like that. Cacatoides seem to adapt fine. G. Kadar ------------------------------------------------------------------------- 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"!