my fish got really sick at one point before i started using stress coat, used it ever since, almost lost my 28'' slilver arow to stress of water changes, now everyones fine, had the tank set up for 3 years and i only lost 3 fish, one got sucked into a powerhead because he thought it was a hiding place (orange finned loach), another jumped out( bala shark),and one got beaten to death(bala shark) by 2 larger fish( BIG BALAS).