Black Tank flush with valve closed

wing_zealot wrote:
WTH you using your black tank for that you need to fill and dump twice then flush for 20 minutes? It's a black tank, its for storing human waste not drinking water. Its going to get full of sh_t again.
I dump mine, throw 5 gallons of water down the commode for a big flush, close the valve, and done.

I'm happy with what I do. I hope you are happy with your approach too.

Yes, and I also do it to help flush out solids, set a timer on my smart phone for no more than 5 minutes.

I do the same thing

At the risk of wandering off topic...

For years I didn't use the rinse system much. If I did it was because I was on a site with hookups and I was generally bored and had a WTH moment. Never did it while at a dump station. I did however sometimes use gray water to back flush, which took maybe 1 minute extra.

Then for the last year I've been using a Sewer Solution and dumping tanks at home. Now there is no "gusher" to help move stuff. So now I'm more diligent about using the rinse system. And why not, I've got a hose out anyway, and plenty of time to do it. Never anyone waiting in line behind me either.

I still think adding a bit of water before storage is important. I don't want the bottom of the tank to look like a dry lake bed. That mud might go back into solution, or it might just float loose in chunks. Why risk it?

Second, I've never seen waste tanks that weren't black. So that was a new one on me.

Yup, mine is some kind of translucent white material. Same thing as the fresh water tank. So when I look down the toilet on an empty tank, I can see daylight through the tank wall. It's somewhat brown-stained, but that's it.

Our rig is nearly 30 years old. I've had it for 10. I never rinse out the tank; I just fill it full before dumping so you get a real gusher when you pull the cork. I used to put the blue "poo pellets" in the tank before a trip, but I quit using them about a year ago. We have no smell issues so I figure it's just a waste of money and unnecessary for the environment.

wopachop wrote:
Is it common for people to close the valve with the hose still running in order to prime the tank with some fresh water?

The guy running my PDI told me to do this - said have your wife look down the toilet while your running the flush. She came around the corner and said tell me what? I said to him, go ahead - you tell her.

I keep my valve open while flushing - have a clear elbow connected to monitor the water color.

After I dump I flush the tank with the cleaning wand installed in the tank. If you don't have one in your tank you can purchase one at most camping stores or on-line. I do this with the valve open and then with the valve closed for about 5 minutes. Occasionally, I have gotten stuff caught in the pipe. If that happens I do a reverse flush from the valve using a hose and an adapter that allows water in and sewage out. I am a full timer, so the rig sits for months in one spot and does not slosh around as one will do when traveling. When done, I fill the toilet with water and chemical then flush. Done!

nazpaz wrote:
I hook the water hose to the tank flush and run it till the black water tank is full, then I pull the lever and dump. I leave the tank flush running for around 20 minutes. Then close the valve and let it run another couple of minutes. Shut it down, and I'm good to go another week.

In our 7th year of fulltiming and doing it that way from the beginning.

If you think you can't remember you are running the tank flush, then by all means don't do it that way. :)

WTH you using your black tank for that you need to fill and dump twice then flush for 20 minutes? It's a black tank, its for storing human waste not drinking water. Its going to get full of sh_t again.
I dump mine, throw 5 gallons of water down the commode for a big flush, close the valve, and done.

rhagfo wrote:

winniman wrote:
Yes, but it is also common for said people to get distracted. This results in a very messy flood in your rv.

Yes, and I also do it to help flush out solids, set a timer on my smart phone for no more than 5 minutes.

I do exactly the same as you, but I set the timer before I turn the water on and I use 4 minutes since I have a lot of pressure here. I have a pressure regulator set for fresh water into my rig, but not for the flush. I want all of the pressure I can get there. Works for me.

I have also saw in two different instances, where rookies accidentally hooked up the water supply hose to the tank flush thinking that they had the hose connected to the right spot. One was a rental C class. They hooked up, and left the rv unattended.It had water running down the stairs after about 20 minutes. The other one was a fifth wheel. We were walking by, and noticed water running out the corner of his 5th wheel. We shut off his water, and knocked on the door. Right about then we heard a scream from the guys wife. I guess she stepped on the toilet lever. It seems the park had two water taps on his site. His new trailer had two hoses, so he hooked them both up, and turned them on. One was for his black water flush, and the water was coming out of his vent stand pipe behind his combo washing machine in the bedroom. Black tank flushes must be done with great caution. They also have been known to leak at the anti syphon valve and flood out an rv.

wopachop wrote:
Is it common for people to close the valve with the hose still running in order to prime the tank with some fresh water?

yes
bumpy