GREY WATER HOLDING TANK TREATMENT

[GPG52_]

PROBLEM:
Our galley grey water holding tank has developed a mild odor. We would like to arrest the problem before it gets out of hand.

QUESTION:
Can you use DOMETIC Premium Holding Tank Treatment (Formaldehyde-Free Formula)in the galley grey water holding tank?

GPG

[ernie1]

I have had the stinky gray water tank along with the troublesome tank gauges that don't read accurately. I made a gizmo that I hook onto my hose with a very small wand which I insert into the bottom of the tank where I've removed the drain plug and fire away in all directions. Always works! No one manufactures and offers any such thing for sale.

[drsteve]

rockhillmanor wrote:
When you flush your RV toilet it is an OPEN straight shot to the black tank. Have that tank filled with raw sewage for more than a day, AND add hot temperatures outside and it WILL smell.

True for the black tank, but the gray water system (which is the OP's problem) is closed. There should be no path for gray tank odors to make their way into the RV, unless there is a malfunction, usually of an air admittance valve or a P-trap with no water in it.

[JimK-NY]

The problem typically starts with food particles. Soap scum also accumulates and attracts more food particles. After a while rinsing the grey water tank does nothing. We use the fine mesh screens on all our drains. That helps but eventually what gets through still accumulates. About once a month, I do a bleach treatment. I use about a quarter cup for every 15 gallons. Be sure to completely fill the tank. Also pour diluted bleach into the traps and pipes. I try to let the bleach do its work for several hours before draining.

[rockhillmanor]

Bill.Satellite wrote:
As mentioned, you should not have black or grey odors in your RV for any reason. If you do you need to find the source of the problem. If you want to make your dumping experience a bit less smelly I like the Happy Camper brand as well but only use it if I am not going to be able to empty for a couple of weeks.

Oh yes you can. The source in the gray is foods stuffs, grease etc. add that to water in a closed tank and it DOES smell.

RV in any of the warmer southern states and 'not' dump everyday? That will smell also. When I am in Florida and do not have hook ups and wait till it's full to dump? I have to add TWO bottles of chems to keep the smell down and even that sometimes does not help.

When you flush your RV toilet it is an OPEN straight shot to the black tank. Have that tank filled with raw sewage for more than a day, AND add hot temperatures outside and it WILL smell.

Your residential toilet has a p-trap that fills with water to prevent sewer gas from entering you house.

The RV toilet does NOT have a p-trap. That toilet flap opens to flush and sewer gas from a full non-treated black tank DOES enter your RV. So every time you flush that blade is open and letting sewer gas and bacteria into your MH.

Push the pedal and hold the flap open and shine a flashlight down, you will see it is a direct shot. This is also how some if gauges are not working look to see how far up the tank is filled.

[TechWriter]

lenr wrote:
Clorox is VERY effective at killing grey tank odor, but is also VERY effective at making the slide valves sticky.

I use bleach all the time, and I'm not seeing this effect.

[Bill_Satellite]

As mentioned, you should not have black or grey odors in your RV for any reason. If you do you need to find the source of the problem. If you want to make your dumping experience a bit less smelly I like the Happy Camper brand as well but only use it if I am not going to be able to empty for a couple of weeks.

[Clay_L]

A couple of people mentioned the air admittance valve. It is on a stub on the sewer side of the the sink trap. It unscrews - usually by hand. If the flap in the valve fails to seal it will allow tank odor to escape under the sink. Replacements can be found in most hardware stores.
No amount or kind of tank chemicals will solve the problem.

[valhalla360]

You can treat the symptom (perfumes) or you can fix the problem (most likely the trap isn't holding water.

There should be no air passage from the tank to the inside of the trailer, so if there is an odor, there is something wrong.

[Dave_H_M]

I would throw an anti siphon valve at it just for grins like ksg suggested jand go from there.

If smells from your grey tank are getting inside the camper, something is wrong in my opinion.

[gbopp]

Try The Geo Method.

[jerseyjim]

I've always used the small bottles of Aqua Chem in my black water tank from day 1. So I have a couple of 6 packs stored in the RV all the time.

Once, I had a bad odor from my gray water tank...put one of the small) bottle of Aqua Chem in it...(just like the black water tank)...odor gone and never came back.

[rockhillmanor]

Add a quart of any liquid lemon cleaner. Fill tank and flush.

I routinely add a quart of liquid cleaner to my gray tank. It cuts any grease that may have formed and keeps the odor at bay.

You can pick up a generic brand of the Lysol Lemon cleaner for a dollar at most grocery stores.

[sdianel_-acct_c]

We use 1 cup of Borax powder dissolved in 2 cups of hot water and add 1 cup of Dawn Platinum dish detergent. No odor. We are also careful of what we put in the dishwater. We wipe dishes before we wash them. No food, grease, etc.

[RJsfishin]

Use what ever you use in the black. Surely you do use something in the black, don't you ? !!!