Winterizing black water tank

[N1VWD]

Hello to all in the group.
I live in VT and I am in the process of winterizing my TT for the year. I have read that after draining the black water tank you should always add 3 to 5 gallons of water to the tank to keep any remaining solids from drying out and keep every thing in solution. Do you still do this at the end of the season? What about freezing, wont it damage the tank? If I drain the tank what about any residual nasties left behind wont they dry out.
All replies will be greatly appreciated.

[W5DOK]

Fill your tank half full with water, add 10 pounds of ice, 1/2 bottle of dawn liquid, drive 10 miles, drain, flush well, and leave empty. Cleans all the crud, leaves a good scent and no danger of freezing and rupturing tank.
Doc

[Radio]

If your going to move the trailer doing the "ice in the tank" proceedure, try running the curbside wheels up on blocks before draining the tanks. That's helpful, too.

[KF5BET]

I purchased a flush king a couple of years ago. One of the best buys I ever made. You can fill and flush the tank multiple times while connected. It has a clear discharge outlet so you can see when the tank is clean (water running clear).

[Andy N1ORK]

For my park model in Freedom, NH, I installed a black tank 'spinner' that hooks up to a waterhose. I turn on the water and it spins water around the tank helping to clean it. I do this a few times until the see through coupling runs clean. I shut off the water, drain the tanks then close both the grey and black tank valves. Then I pump RV anti-freeze through the system. The excess goes into the tanks. This procedure works well for me.

[KC1BUD]

Originally Posted by Andy N1ORK

For my park model in Freedom, NH, I installed a black tank 'spinner' that hooks up to a waterhose. I turn on the water and it spins water around the tank helping to clean it. I do this a few times until the see through coupling runs clean. I shut off the water, drain the tanks then close both the grey and black tank valves. Then I pump RV anti-freeze through the system. The excess goes into the tanks. This procedure works well for me.

I haven't used it yet but my Damon Motor home has a flush kit installed from the factory.
However I did purchase a 4" section of clear black water pipe, like the one pictured below, available at most RV stores. I connect this in between the hose and the valve.

This way I can see when it runs as clear as fresh water.
Back to the OP's question; After a through rinse and flush, other than the antifreeze that gets past toilet's gate valve, I leave the tanks dry. Have never had a problem in all the 30 years of RVing.

The only problem(not really a problem) I have with this is my Daughter's two oldest sons, 8 & 10, they have seen the movie RV, and now when my daughter's family are at the horse shows with us the boys have to watch grandpa dump the RV tanks when we are leaving.





Dan

[wa8yxm]

As someone said, Fill with 1/2 cup Dawn, (Regular NOT anti-bacterial) 1/2 cup Calgon water softener (Powder or liquid) and .. Well I go 1/6th water but I drive farther, say 1/3 water. Drive a while, making turns and such to slosh it around good.. DUMP, tank will read FULL (which it is.. Full of bubbles) give it a couple days for the bubbles to pop and dump again.. Then add around a quart of "pink stuff" down the toilet, then some more in the toilet (Water pump off no city water hook up, bleed pressure off water system before you do the last dump, in fact winterize fresh water system before last dump)

Pour pink into the drains for the traps, and walk away. This should take care of it.

NOTE: same for the gray tank.