I have peristaltic pump and 15 gal tank for liquid chlorine. I keep the tank at 8.25% concentration because that's how I usually buy bleach. From time to time I pickup 10% at Home Depot, in which case I add 27oz of water per gallon to get it back to 8.25%. I always assumed it would mix by diffusion, but then I saw the Liquidator floats a layer of water over the bleach. I don't understand how that works, but then the question is do I need to stir my tank after adding 10% and water?