Combine this product with Yachticon clean-a-tank product to clean or tank and you end up with a relatively clean tank. It will not clean a tank (even with clean-a-tank) that hasn't been cleaned for years, you have to do a hand wash of the tank.
We ordered three bottles. All three were covered with an illegible sticker on the back (above the instructions for use). Who came up with that? In addition, where there was enough space under the instructions for use.