Hello Raymond I have a python to do water changes with. I also use buckets some times to do water changes. When i use my python to do water changes I only change about 25-30% of the water. When i fill the tank back up using straight tap water, i use a dechlorinater from Aquarium Pharm. called Tap Water Conditioner. I squirt a little bit into the tank as I am refilling the tank. Never had any losses or problems doing this. Just a "Fear Note" or caution i never use a python on fry tanks. Just afraid that the fry are too sensitive to the new water, dont want to lose a tank full of fry cause i was being stupid. I know this is stupid but i feel that way sometimes. I do gotta admit even with all my 60+ tanks, i still use a hose and bucket method on most of my tanks. Takes me longer but I hate hooking that hose up to the kitchen sink sometimes. Also I've been doing it that way for so long i don't even think about using the python most of the time. I do use it on my bigger tanks, anything larger then a 20 long always gets the python. But i only have 6 55 gallon tanks and 8 20+ gallon tanks, everything else is a 10 gallon or smaller tank. John Wubbolt ------------------------------------------------------------------------- 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"!