The white worm like creatures you see in your tank are probably planarians. These seem to appear whenever heavy feeding of fish is done. I used to see them often when I had discus which I were feeding heavily. They are harmless to fish and to get rid of them feed a bit less and do more frequent water changes. I don't think nematodes and feeding microworms are connected. The nematodes that affect fish (camallanus sp.) can be seen hanging from the anus of fish and are red from the blood they get from their host. Ken. ***************************** Ken Laidlaw UK Astronomy Technology Centre Royal Observatory, Edinburgh Web: http://www.roe.ac.uk ***************************** ------------------------------------------------------------------------- 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"!