Furnace/Battery Help and Black Water tank

I do use the BLUE stuff a lot.

Thank you for the information on the Blaster. Went onto Amazon and ordered one. Now have to decide where to go to use it.

Thank you.  

  I had a Tornado installed in our black water tank when we bought the POD and have never had a problem with the sensors. That was one of the many things that I learned on the forum before we purchased the trailer. Put a clear section on the end of your sewer line and you know when your tank is clean.  Goose

When you go to buy the 'water wand' clean out device...check to see if it has a twist water valve on the top of the handle (mine did).  That way you can shut off the water at the wand.  My wand also came with a larger diameter plastic tube which you insert into the toilet to keep the toilet valve from closing down on the water wand.
Hopefully you had at least a quarter full tank to slosh around while driving over to the dump station...this helps loosen any sludge which has settled to the bottom.  A full (or 'empty') tank won't slosh and doesn't self clean as well as a quarter full tank.
I prefer to clean a drained tank when using the wand, that way the wand's spray will hit all of the interior surfaces of the tank rather than spraying ineffectively into water on the bottom of the tank.
1) shut off the water pump; 2) open the toilet valve completely; 3) insert the larger plastic tube (it should have three or four flange tabs which extend slightly larger than the toilet valve to keep the tube from dropping too far down the drain; release the toilet handle, the valve will close on the tube; 3) Make sure that the wand valve is not leaking (you don't want water spraying all over you and the bathroom; 4) before inserting the wand look at the lower end and find the spray hole(s) and their orientation to the wand valve handle; 5) insert the wand gently (the toilet drain has several cross pieces down below you need to go past); 6) turn on the wand water valve slowly (if the spray hole is positioned against the drain pipe, the spray may want to shoot back up at you);  7) increase the water spray and slowly rotate the wand so that the spray shoots out and hits all the sides of the holding tank; also raise and lower the wand so that the spray hits higher and lower; 8) don't get so involved that the tank fills completely and overflows the toilet, the last couple of inches fill really fast!. I usually fill the 'cleaned' tank nearly full. 9) shut off the hose valve, extract the wand, while holding the toilet valve open remove the larger tube.
Drain the tank at the dump station...when the tank is drained...flush the toilet a couple of times so that any remaining sludge is washed out. Close the drain valve.
Add the recommended amount of tank chemical and flush a couple of more times. (I add some tank chemical even if I am winterizing and RV antifreeze will be flushed down into the tank)