Cleaning out the grey tank

[Mr. T]

My sensors on the grey tank are no longer accurate. I'll be driving the coach in a couple weeks and plan to put a cup of dish soap down the drain and drive it with the tank about half full.
Any other options for something that might be better?

[Lt Dan]

Use Dawn dish soap and add about a full cup of Calgon water softener.

[shootist]

7 gallons of water per 50 gallon tank capacity, 1/2 cup of dawn and a 4lb box of borax. 20 minute drive in town with lots of turns. The tank will sparkle.

[dons2346]

Go to the dollar store, get a bottle of cheap dish soap and a box of cheap water softener. A cup of dish soap and a cup of water softener dissolved in a quart of warm water in the tank. Then 10-20 gallons of water and a good drive to your next camping location then dump.
No need to buy the expensive soap and water softener.

[Dennis C.]

I can’t say enough good things about Happy Campers RV Tank Treatment. We have been using it for years and it’s an excellent product. It keeps your tanks clean and free of odors. The regular tank treatment is great for normal use. They also sell an extreme cleaner for situations like yours. The service department at my local RV dealership told me that treatment with these products is the first thing they do when servicing a rig with holding tank issues.

https://www.happycampers.store/

[MrMark52]

Cleaning of black or gray tanks requires the following to be successful -

Time
Temperature
Concentration
Agitation

The above otherwise known as the TACT principle.

The cleaning solution needs to be aggressive (the difference between hard and soft water is where soft water is aggressive - and this is accomplished using Borax or Calgon dishwashing soap. Hard water isn’t aggressive).

Dawn dishwashing soap is an excellent degreaser relative to other detergents while being more environmentally friendly (remember the TV commercials of the little duckies being bathed in Dawn after an oil spill).

For a MoHo - temperature is the only 1 of the 4 principles that is harder to accomplish.

Many of the above suggestions are valid - provided the indicated procedural steps are understood.

When you think about it, water alone with heat is a pretty good cleanser - ever have a pan with burned on food where if you took that pan and placed over heat (cooktop) with water in it, and allowed the water to boil without boiling away - the food will for the most part will loosen and lift away from the pan.
Time, concentration, and agitation only help to promote what can’t be achieved with heat.

[Dutchstar411]

I used Dawn in both, mostly at the end of the trip with water in the tanks as well. Since then, I have never had a sensor issue. I also use warm/hot water since I can with my outside faucet.

[Mr. T]

Thanks!
I wish Newmar would have added a rinse option like the one for the black tank.

[Dennis C.]

Newmar installs a grey tank rinse system in the luxury coaches. The New Aire that we almost purchased had this feature.

[Dutchstar411]

Originally Posted by Mr. T

Thanks!
I wish Newmar would have added a rinse option like the one for the black tank.

I hardly ever saw my grey tank say "E" after dumping. Now after leaving some water in the grey tank with Dawn when we leave a camp site I always will see "E" once I dump it when we arrive at a new camp site. And other levels if my tank is closed when camping.

[Persistent]

Lots of good advice posted above. I agree with Dutchstar 411 the most. A little detergent a partial fill with water and lots of driving to agitate.

I would be careful about additives like Borax. More is not better. Find the recommended concentrations and don't exceed them. I tried many products like that and found that even plain water with lots of agitation works extremely well. Over dosing works poorly.

Don't flush grease or any more food particles than necessary. Wipe dishes and pans before washing.

[mbrooking]

We used this and it cleared up our sensors....
https://www.amazon.com/Unique-RV-Sen...grid_rp_0_12_t

[Camp CA]

Great discussion........Camping Advisor refers to many of the above methods as the Geo Method Recipe https://thecampingadvisor.com/geo-me...-calgon-borax/.

[PetesMH]

I drop a dishwasher packet in both tanks every now and again. I think it works better than dishwashing soap, it’s easier and it is low suds which I think is a good thing.