Sludge in gray water tank

[ojnark]

My gray water gauge indicated some volume after I had emptied the tank. I took it to the dealer and he said it had a lot of sludge in it and was making the gauge stick. They flushed it out thoroughly and the gauge now shows empty. When I bought the trailer 1 1/2 years ago, they instructed me only to drain the tanks every few days and not to leave them open. When I told them I was leaving both the gray and black water drains closed when hooked up to sewer and only opening them every few days, they said that soap, grease, etc., in gray water probably had caused the sludge buildup since it was just sitting there. They then told me from now on to only leave the black water drain closed when hooked up to a sewer connection and to empty it every few days but leave the gray water tank open all the time. Since the dealer only used water to flush out my gray water tank, I want to make sure that all of the sludge is out so I would like to put in some cleaner of some sort that would dissolve any remaining sludge. Has anyone else experience this problem and found a good cleaner to use?

[Herk7769]

Hair from the shower and soap will build up on the walls (and sensors) over time. The "cure" is prevention.

I keep both closed till ready to dump; but I pre-treat both tanks with 1 capful of liquid Calgon and a capful of liquid laundry soap (a few gallons of water in each as well). This keeps things in solution and the tank walls (and sensors) slippery so not much sticks.

They will always show some water (the 1/3 light) as soon as you put any water in the tanks due to the location of the lowest sensor. It is NOT a 1/3 light; but a "Not Empty" light.