Approx. time to run black flush for partial refill

[Riverbug]

Until we purchased our new unit this summer, I never had a camper with the black tank spray valve. I always used the toilet bowl filled a few times to flush out. I did that on our first trip before remembering the sprayer valve. I was really surprised at how much more gunk came out. We have a clear elbow so I left the valve open and it must run about 5 minutes before it's all clear. I could tell when more was coming because the water out the hose would slow or stop until the water in the tank built up enough to push the next "batch" out and down the sewer hose. It was quite enlightening (and disgusting) to realize all those years of flushing the old way in previous campers and motorhomes must have left a lot in the tank that I never realized. Then again, it never hurt me so...

[4x4dually]

I put a clear 45 deg adapter between the RV and the hoses going to the dump. I run the flush until the water gets clean and stays clear. Typically when it gets clear, I'll close the tank valve and let it fill for a minute or so, then open the valve again. There are always a few chunks that come out after that. I'll do that a couple times.

As posted, varying pressures and flow rates will make it almost impossible for you to put X gallons in the tank every time. I guess a bucket in the toilet would be the only true way to properly gauge it for accuracy if you are worried about it too much.

[JM0397]

I use an inexpensive inline flow meter (also helpful to monitor water consumption and/or for filling the fresh water tank. I have 2, I don't use anything dedicated to black tank elsewhere).
Drain black, put back in about 10-15 gallons through the black tank flush valve, drain again, then refill with 5 gallons of water, +blank tank treatment, +about a cup of Pinesol. If the second draining still looks funky and I have time, I'll flush & drain a second time.

[4x4dually]

I use an inexpensive inline flow meter (also helpful to monitor water consumption and/or for filling the fresh water tank. I have 2, I don't use anything dedicated to black tank elsewhere).
Drain black, put back in about 10-15 gallons through the black tank flush valve, drain again, then refill with 5 gallons of water, +blank tank treatment, +about a cup of Pinesol. If the second draining still looks funky and I have time, I'll flush & drain a second time.

What device do you use to put the treatment back in the tank? Are you injecting it through the flush line or dumping it in the toilet?

[JM0397]

What device do you use to put the treatment back in the tank? Are you injecting it through the flush line or dumping it in the toilet?

Just the usual powder stuff, don't recall the brand name now, but mix a scoop into the toilet & flush. Same for the Pinesol, just dump it into the commode.

Also, full dump, refill, dump, add 5 gallons, and dump both gray tanks, runs about 15 minutes but a lot of that depends on the flow rate when adding water back in, and if I'm already hooked up to sewer or passing through a dump station, in which case add about 5 more minutes. Also, the Solitudes have massive tanks, so might take longer than other models, I think about 50 gallons each for the 1x black and 2x grey.

[Riverbug]

What device do you use to put the treatment back in the tank? Are you injecting it through the flush line or dumping it in the toilet?

I saw this interesting article. Haven't tried the Pinsol/Calgon mix yet, so I cannot attest to it, but bought the stuff to try in FL when I use up our bottle of Thetford...
https://kleentank.com/which-tank-additive-is-best/

[IBEW Sparky]

My tank emptying process is as follows:

- Empty black tank
- Empty kitchen gray tank
- Empty bath gray tank
- Flush black tank until runs clear (about 15 minutes); close black tank valve
- Fill five gallon pail with water
- Put a gallon of water in toilet, along with scoop of Happy Camper; flush
- Flush remaining water into toilet

Obviously skip last three steps if going into winter storage.

John

Just a suggestion but it's always a good idea to leave dumping the bathroom grey tank for last. I do the black tank first with a short flush towards the end, close that valve and then next I empty the kitchen tank and let water fill the black tank simultaneously through the flush line.o Once kitchen has drained I close that valve and shut off black tank rinse. Next open black tank drain and do a second rinse and 3rd if needed. After I'm satisfied with the black tank I close that valve and then open the bathroom grey tank and let it fully drain. This helps give a final wash out to the discharge pipe, sewage hoses, and all of my fittings. If I'm traveling directly to another campground with full hookups I'll let the black tank fill for 2-3 minutes while draining the bathroom grey tank.

[ba3jbrown]

I think I've been overdoing this. I do the same as Sparky but fill black 1/3- 2/3 and keep flushing till the clear 45 adapter shows very few solids and clear water.

[SlimJim]

I'm confused... I thought the rule was to never use the black tank flush after closing the valve? I guess a little would be ok, but doesn't it get pressurized?

[Linndoren]

Hi. Can anyone give me an idea of how long to run the flush in the black tank once the tank is emptied & clean and I close the valve to refill? I'd like to fill a few gallons so I can add Happy Camper inside. I typically let the black flush run about 5 minutes. Have no idea if thats enough time to refill a few gallons or not. Thanks in advance.

I run the sprayer for 1 min after completing my flushing regimen. I only run for that short of time to ensure flow rates don't need to be calculated nor measured. I will also leave 1 min of water in the black tank for moving day as well to help clean the sensors.