If I do a 25% water change on 90g tank using Python system will it hurt to put the recommended WC into tank first then fill. Before I woud leave water sit for 6-8 hours for my 30 gal. Now that i have bigger tank and changing 23 gallons at once from tap will this shock the fish? I hate to have to pump the water back into tank if it's not that much a big deal for the fish safety.
. I use the EXACT same method. What benefits do you get from letting the water sit? I dont have that much time on my hands.