[BB_TX]

Forget the tank level indicators. For flushing you don’t need to fill the tank near full. Or even half way as far as that goes. Get a short clear plastic extension to connect to your sewer outlet ahead of your sewer hose. As mentioned above, get a flow meter and run the flush to a desired number of gallons. Drain and flush again. And maybe a time or two more. You don’t need completely clear water coming out. When you see most all of the solids stop coming out, you are good even though the water may still have a little brown color.