I have used Magica for years. It is the only product that does exactly what it says it does. It is expensive and worth every penny. We are on a well and septic system. Even though we have many filters before it gets to our house water, rust stains appear in all of my toilet bowls. I tried every other product on the market nothing worked until I discovered Magica. One of the toilets was not flushing properly. We were afraid that the septic tank had to be drained. I suggested we squirt some Magica on the handle, both inside the tank handle and outside, on the handle where it joins the outer toilet. It worked like magicA. Toilet functions perfectly now. I LOVE THIS PRODUCT! Thanks.