I've never been to Egypt but I have seen a pryamid. (Black Tank Tps)

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Our tanks were cleaned yesterday and lessons were learned. I'll post tips from the tank guru. (Black Pyramid or TEE-Pee had formed like concrete in the black tank) I have not proven these tips but they come from people who clean these thing for a living.

1. KEEP ALL TANKS CLOSED. Let water out as needed for showers but keep all tanks closed - even when hooked up to campground sewer. Dump gray tanks when black tank is dumped. Not an absolute but liquid soap is better than bar soap for the tank. If using bar soap it is even more important to keep gray tank closed. Bar soap will reform and dry solid if left exposed to air on any surface. If tank has no water in it the soap tends to dry in the tank.

2. 8 second flushes. Let water run for at least 8 seconds.

3. Use no chemicals. Use 1gl jug filled with 48 oz of Pine-sol, water and 1/2 of Calgon Bath Beads (No Substitutions) found at Walmart. 8oz into black tank and 4oz into each gray tank.

4. GALLEY gray tank will get as funky as the black tank if not taken care of properly. Keep fine mesh strainers to block food particles from entering gray tanks. Keep closed unless dumping - treat galley tank like black tank.

5. As always, dump black tank when full. However, fill black tank completely full and rinse - twice. Close black tank and fill with water to 1/3 mark. Add Pine-sol/Calgon solution.

6. Tech believed (his theory- not provable) that the combination of high ambient temperature, commercial Rv tank chemicals, and biomat solids in the black tank create most problems inside these tanks. NOT 2 PLY TP. As long as enough water is used when flushing and dumping there will not be a problem in the tank and any kind of 2 ply tp can be used. Water, water and then more water.

We get a second chance at maintaining the tanks as we have NOT been using enough water when flushing AND dumping since day 1. I think if one follows at least some of these tips, the only pyramids you'll see will be the ones in Egypt.


  1. Brent M's Avatar
    Good tips! We never really bothered with being selective on the TP we used, but it's critical to have enough liquid I believe. A couple other things I did. After flushing, hook outside shower to black cleaning outlet and run black tank jets on hot water for a couple minutes. This rinses the empty black with hot water. Then close black tank and run jets for another minute or two. While running, put dishwashing liquid into toilet and flush it down into tank. This leaves warm water in tank with dishwashing liquid to slosh around as we move to the next location. I've never really concerned myself with adding soap to the gray tank, but certainly a gallon or two of water as well. Grays get dishwashing liquid and/or liquid soap. I think I'm going to change to keeping the tanks closed now that I know our galley will be separate from the shower. Love hearing what others do.
  2. partsguy009's Avatar
    I've used the same method over the last 10 year's and knock on wood have not had any issues.


    Normal Flush Steps: Helps keep hose clean.
    1) Black Tank
    2) Grey Tank

    Final Flush Steps:
    1)Black Tank "Leave Open"
    2) When you hear a trickle turn on Black Tank Flush
    3) Grey Tank "Leave Open"
    4) Flush Grey Tank
    5) Turn everything off wait for all to drain, close tanks and follow chems below.

    Black Tank: I add at least 8oz of Aqua-Kem by Thetford after every dump plus 1-2 gallons of water through the toilet. On final dump before breaking camp I run the black tank flush for a good 5 minutes with the tank trap open. Once completely drained i close the trap and add 8oz of Aqua-Kem, 4oz of Murphy Oil Soap and 3-4 gallons of water. This solution allows the tanks and sensors to be washed while being towed.

    Hint- Water helps the medicine go down..

    Grey Tank: I follow the same procedure as the Black Tank except you need to run all your faucets including your shower to fully flush the grey, no hose hookup for flushing. I use Grey Water Oder from Thetford and still use the 8oz plus water after normal flushes but add the Murphy Oil Soap after final flush.

    Hint- DO NOT place food or drinks down your sinks, bacteria will cause bad oders.

    Hope you find this helpful.....RVing should be fun and smell good

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