not to revisit an old topic. but I was wondering if this method of dechlorinating water works for everybody?I change about 40-50% each week using my python. Add the dechlorinate at the recommended dose for a full tank. I add about half before it starts filling and the rest as it fills. Not lost any fish yet with this method. I've got a bathtub fairly close to tank and use that. It is lower than tank and drains and fills tank fine.