Black Water Tank

[Parrothead]

Like most people above we use septic safe TP, 2 ply. I like Charmin the best but that is just MHO. We use to use chemicals but thanks to the MOC found we didn't need them. We use Calgon or Borax and lots of water. When parked we keep the galley open. Have done this for years and never had a problem. We wipe everything with paper towel before washing. And lots of water goes through. Since we have the W/D, the gray has to be open when we are doing laundry and then we close it.
Unlike Dennis we did notice some odor when our temps were 110 and over and we used some chemicals then but discontinued them when we got out of here to cooler weather. We use the back flush until it runs clear to fully clean the black tank. This takes 4 or 5 times usually. I think we will try the Pine Sol this spring but it will have to be the lemon scented as the original causes asthma for me.
Again to each his own. What works for some, may not work for others.
Happy trails.......................

[rickety]

Laundry detergents and fabric softners both cause "crusting" in septic systems, because the two chamber systems flows liquids into thelarger chamber and holds the black stuff in the front chamber.
Laundry detergents have fillers andsurfactants in them, Fabric softners have oil in them to replace oils lost in the fabric washing process. These all combine to cause crusting. IMHO you won't have to worry about crusting in your holding tanks, because the liquids aren't held long enough to start the process.