I vaccum the gravel, removing about 20% of the water, and then begin to fill my two 5 gallon home depot buckets with tap water. I put a couple of capfuls of stress coat in each bucket, wait for a minute or two while I re-arrange any driftwood or plants I may have disturbed, and then put the new fresh water in one bucket at a time. I've been a little skeptical about the python, because of the dechlorinator issue. After reading the posts here I am beginning to feel better about it. It would definitely be easier.