Right on the money Jim, I knew there was a formula for the ratio, but I aint smart enuf to remember it
. But you might want to add that, at water changes, you NEVER want to have more than a 5 DEG. water temp change at a time, As I stated earlier I use a 30 Gal. tank(yellow tank in boat in avatar), when I need to do a water change, I get out in no less than 60' depth, then pump out just over half of the water from the tank, then drop a 30' Garden hose W/ weight and a screen on one end and a Sunami 750 GPH pump on the other, I let it pump back into the lake till the water is cold , then refill the bait tank with water from 30' deep, clean(no oil or mud), and cold. I change the filters and add more salt also.This way I dont have to use my beer ice
to keep the bait healthy.