Campa Chem by Thetford

Do not use this product! It damaged my newish blackwater drain valve shortly after using this product. The valve started leaking and not holding it's seal the very first time I used it and things got progressively worse because I didn't realize this stuff was the source of my problem. When I got back from the last rv trip, I pulled the drain valve and took it apart as much as I could and found a buildup of the Campa Chem material around the slide area and it appeared undissolved. After thorough rinsing of the valve, the Campa Chem substance still did not dissolve and appeared gritty. So I did a test of this stuff and soaked it in a very large container of water overnight and found that it still did not dissolve.

I called Thetford and found out that the material is silicon dioxide! SAND! That's why my dump valves have taken dumps in the past. The sand acts as an abrasive and tears up the seals and slides. I understand that silica is put into products as an anti clumping material but silicon dioxide or sand is a recipe for failure if used in holding tanks with dump valves. Do not buy nor use this stuff which I got from Walmart.