Plug in the black tank

**rbgntx** · 04-15-2023, 04:11 PM

In the last week or so our blank tank seems to have picked up a partial blockage. I am able to drain it and run water through to flush but the flow from the drain hose is slow and the water backs up towards the toilet bowl before slowly draining down. We are pulling out and heading for our camp host locale in Oregon in a day or two. Somewhere I've seen it suggested to put ice in the black tank and then drive all day to let it shake things up, then drain the tank again. Has anybody tried this and, if so, how much ice was used. Thanks for any input.

**MoonShadow_1911** · 04-15-2023, 04:47 PM

I have used this: Bio-Clean Drain Septic 2# Can Cleans Drains- Septic Tanks - Grease Traps All Natural and 100% Guaranteed No Caustic Chemicals! Removes fats Oil and Grease, Completely Cleans Your System. https://a.co/d/96Ursum to good effect, but it does take a couple of days.

I put it in my black tank, asking with the regular bacteria tank treatment I use, and it cleans it my tank pretty well.

I've never had a blockage, so I can't talk to that.

**robmcqueen** · 04-15-2023, 06:55 PM

Try one of these. https://www.amazon.com/Camco-Feature...1&sr=8-10&th=1

**FlyStar** · 04-15-2023, 07:59 PM

Mine had a partial plug once. I closed the valterra valve that I put where the slinky connects (a good idea to have one of these) opened the black tank drain then opened a full grey tank drain. The warm shower water ran backwards into the black tank and dislodged the plug.

**jmbopp** · 04-16-2023, 05:58 AM

Originally Posted by robmcqueen

Try one of these. https://www.amazon.com/Camco-Feature...1&sr=8-10&th=1

I replaced my sewer caps with ones that have a garden hose nipple on them. I use a F-F adapter (or old washing machine hose) to backflush the tanks.

**DougW9876** · 04-16-2023, 06:27 AM

Put enough water in the tank so it is half or two thirds full and drive it. The sloshing should help loosen things up so they will drain out when you dump it. The ice would help but I have always wondered how long the ice lasts and how much good it really does. Fabric softeners or detergents would help to break the solids down if it is really badly plugged.

**huntindog** · 04-16-2023, 07:42 AM

Originally Posted by jmbopp

I replaced my sewer caps with ones that have a garden hose nipple on them. I use a F-F adapter (or old washing machine hose) to backflush the tanks.

This has a high chance of contaiminating the spigot water supply....

**kb0zke** · 04-16-2023, 02:11 PM

A trick we learned years ago is to dump when you ARRIVE at the campsite, rather than when you are leaving. The motion of the trailer going down the highway really gets things agitated, so everything dumps easier. The tank washing feature is something that we didn't have before, and when I run it after a day's drive I really get clear water fairly quickly. We've been in our host site since 29 March, and I haven't seen completely clear since that first dump.

**jmbopp** · 04-17-2023, 07:10 AM

Originally Posted by huntindog

This has a high chance of contaiminating the spigot water supply....

Not if you use a shut-off valve, check valve, or anti-siphon valve.

**sande005** · 04-17-2023, 08:57 AM

Ice does nothing!
Get a Valterra Flush King (includes a check valve). Close the main valve on it, and use the hose connection to back fill your tank via the main sewer line. Use a water meter so you don't overfill your tank.
May have to do it several times.

https://www.amazon.com/Valterra-Degr...s%2C115&sr=8-2

https://www.amazon.com/P3-Measure-Ga...04&sr=8-6&th=1