How to prove that the water pipe is rusty or that the rust has stopped?

"Water pipe descaling softener" can help you solve the problem. Under the known circumstances, the following obvious effects have been achieved after adopting the "water softener" which has obtained world patents (64 national patents): 1 can be used to prevent rust and scale in newly installed pipelines for a long time; 2. The pipeline that has been blocked by rust and scale will slowly remove the rust and scale, making the interior of the drainage pipe very clean (it will have obvious effect in about 3-6 months). 3. After derusting and descaling, a protective film is formed on the inner wall of the exhaust pipe to prevent the formation of new rust scale. (excerpt:://tksboy.b2b.hc360.com/shop/product.html).