Hi Ken, I'm living in equatorial Singapore, and the pH of my tank is 6.5, the swordtail family have been in the same tank for the past 2 years and for generations. Temperature in my tank has been constant throughout this time, as in the equator, that doesn't change much. I'm quite sure it is not the temperature nor the pH that is causing the problem. Come to think of it, could I have stressed them due to overweeding my aquatic jungle during the water change? I'm just crossing my fingers now that one white spot has just been shed by one of the swordtails, and will be looking at them closely now. Cheers, Kenny ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!