You don't need to add any chemical when using the steel wool. Just keep it moist. If you really want to do windex, you could only use it on the outside. If you get windex into your tank, you could kill your fish (it has ammonia in it). Some glass cleaners are ammonia-free, but the active ingredient may be dangerous in your aquarium water.woulld windex work w/ steel wool or would it create a chemical effect that will blow my tank up?