My over flow tank has some black inside from some thing. I figure I can remove the tank use some thing like simple green, Krud Kutter or other with some water. Got another idea? Al
I used CLR and a handful of steel washers. Let soak for a bit and shake the washers around until it's clean. Might need a magnetic grabber to get all the washers out so don't do what I did the first time and use stainless (or pennies). ;-)
I have used Bleach before. Top the tank up with Bleach and store safely overnight. Works well, real well.
HOT water, any laundry detergent or dishwasher detergent (doesn't suds as much as hand-wash dish detergent) and a few fistfuls of playground sand. Shake vigorously. Let the sand and detergent scrub the inside of the plastic tank.