Storing the RV for 3 months Water or No Water in the Black/Grey tanks?

[JohnC3]

We are storing our full time RV for the 1st time. We will be gone for 3 months. It will be stored in AZ from OCT to JAN. The tanks will be flushed as clean as we can make them before storage.  I am wondering is it better to store the Black/Grey tanks with water or dry. I am thinking that if I put water it will just allow for growth in the tank over such a time. What's the prevailing wisdom?

Thanks,

John

[Bob Jones]

Just my .02 - if freezing is not an issue I would leave the black tank full of fresh water and put a Green Gobbler in it. I would use that time to get all the crud out of it. I've found, when flushing the tank, even leaving it full with fresh water over night gets even more out. But I'm a little weird that way 🙂

[CLIFF918]

John,

I have always put about 1/4 tank of water and add a tank treatment of your choice while adding the water. Has always worked for me.

[Ivan K]

For me works to leave at least enough to keep the dump drains submerged so they don't dry out, same for the toilet seal but lid up. Some treatment is a good idea, I used Happy  Camper for longer term.

[Tom Cherry]

Like annal orifices, which each supposedly has, this would be my take.  It is a “evolution” of learning here and personal experimentation.

I have to winterize.  So I use compressed low pressure air and then refill with RV antifreeze.  I over “discharge” the pink stuff so that I have maybe a gallon in the gray and half in the toilet.  I then dump the tank so the Sanicon has almost pure pink. 

If no need to winterize, first remove the water filter and and if possible, install the bypass line.   I’d probably drain the fresh tank.  Purge the entire system with CITY (Chlorinated) water…using the “city” position.  Then put maybe 10 gallons of city water in the tank…..disconnect the city line and dump out whatever comes out of the fresh tank.  If there was no chlorinated cit water. Mix up a gallon of water with about ONE TEASPOON of STANDARD HOUSEHOLD BLEACH. (5.25%]. IIf CONCENTRATED (8.25%), about 2/3 teaspoon.  Put into the empty fresh tank.  Add 15 -20 gallons.  That will give a 2 PPM or so mixture.  City water is typically around 1.25 - 1.5…with a max of 2.0 or a smidge above.

Add 1 scoop of Happy Camper to the Black & 1/2 scoop to Gray….probably mix each with 2 quarts or so of water.  Dump into a sink as well as directly into Black.

That leaves a solution that will keep the bacteria active.  Both the tanks are “septic”….the gray has food scraps, so not as potent.

i used to fanatically drain the tanks each time it went to storage.  Now, I leave them as above.  I think I have less built up crud.  I still back flush the blacks and clean it occasionally.  My sensors are always wrong, but seem to be closer.

Wise folks that used their rigs frequently as well as full timers have less issues with valve and sensors.

My take…others might differ…but it does or would work in the scenario presented.

[waterskier_1]

You don't say where in AZ you will be storing your coach.  If in Flagstaff, Gallup, or the mountains, you should winterize.  Last year many coaches that were not did freeze, maybe not enough to damage the holding tanks, but it did burst plumbing.  If you are talking Yuma, that is totally different.  

Like Tom, I have to winterize, several times a year.  If you have an Aquahot, do NOT use compressed air - that method will likely cost you $10K.  You must use RV antifreeze to ensure there is no water left in the 30 miles of copper tubing in the Aquahot.  

There is no good reason that winterizing with RV antifreeze can hurt anything (besides your pocketbook).  I get mine at Walmart for around $3/gallon.  

  -Rick N.

 

[JohnC3]

Thanks everyone for the great responses.

Since I will be storing my Camelot near Phoenix, I don't believe winterizing will be required. I will leave the Freshwater tank dry and the black and grey tanks Clean except for ~10 Gallons of water and a treatment of happy camper.

I appreciate all your comments and suggestions,

John