Black Tank
Pasted below are are a few tips:
1. DUMP A FULL TANK
When you are camping and your RV is connected to a sewer/septic intake, leave the drain valves closed until the tank is full and ready to dump. Dumping a full tank provides a sufficient quantity of water to flush solids from the tank. Leaving the drain valves open allows the water to drain off without flushing out solid waste. That solid waste will collect in the tank(s) and cause problems over time.
2. DUMP TANKS IN ORDER FROM DIRTIEST TO CLEANEST
In other words, dump the black (commode) water tank first, then dump the grey water tank, then dump the potable water tank. This way you will be flushing out the dirtiest water with progressively cleaner water.
3. USE WATER SOFTENER
This stuff is amazing and it works. Buy a couple of boxes of powdered water softener at the grocery store. You’ll find it located with or near the laundry detergent products. I prefer Calgon Water Softener because it dissolves quickly in water. Cheaper water softeners work just as well but dissolve more slowly. Dissolve two (2) cups of the water softener in a gallon of hot water. Then, pour the solution down the drain into the empty tank. Use two cups of softener for each wastewater tank in your RV. The tank’s drain valve should be closed otherwise the softened water will just drain out. Then use the tank(s) normally until it is full and drain it normally. Add a cup of laundry detergent to the black (commode) water tank at the same time. This will help clean the tank. The gray water tank should already contain soap through normal use.
The water softener makes the solid waste let go from the sides of the tank. Softened water also prevents soap scum from sticking in the tub. With softened water gunk washes away instead of sticking.
Note: If you add a bag of ice to the black and grey water tanks after each draining, it'll help remove any build up and disolve it at the same time while traveling back home.
Another note: Scott Toilet Tissue just came out with an "RV Friendly" / "Septic Tank Friendly" tissue. It can be purchased at BJ's. It's the best one found for both RV and home use.
I use one of those clear plastic elbow connectors to attach my sewer drain line to the wastewater outlet on my RV. It allows me to see how well things are progressing during a wastewater dump. Before I began using water softener regularly the black water tank’s water was brown, the grey water was brownish and the potable water was white. The first time I added water softener to the tanks the water coming from the black water tank was actually black (not brown) and the grey water was also black (not brownish). The potable water remained white. That told me that the water softener had actually done what I had intended for it to do and made solid waste, which had been stuck to the interior of the tanks, let go and drain away. I added water softener to all the wastewater tanks for the next few dumps to be certain all the solid waste possible had been cleaned away. The wastewater only appeared black on the initial treatment. I now add water softener to each tank once after every few dumps to maintain the system.
Occasionally, I pour a gallon of liquid bleach into each tank to sanitize and disinfect them. I no longer use the blue toilet chemical because it isn’t necessary. I have no odors coming from my black water tank. Generic brand liquid bleach is cheap and very effective.
