Vinegar or Baking soda

I don't think you'll find many folks who go to that extreme to clean the waste tanks. Usually it's not necessary if they're functioning as they should. There are chemicals you can get for freshening, but they don't need to be sterile. I usually just dump and add a1/2 gallon or so of rv antifreeze to protect the seals and call it done. Maybe abit more in the black tank. Never had a problem.

I think using dawn and some calgon to soften water and the bag of ice cubes and drive around is very effective. Then if you don't have a built in cleaning valve get one of the cleaning wands that connects to hose and is inserted from the inside. That should clean it pretty well.

Try The Geo Method to keep your tanks clean.

They don't need to be sterilized.

the OP... NO

baking soda will only freshen the smell of the empty tank
its actually a decent way to freshen your fresh water
put a spoon full in your hose before you connect and turn on the water

vinegar is a mild acid..don't know if it would help or hurt
i have doubts about it doing any significant cleaning
maybe if you used a few gallons

RVChippys wrote:
Has anyone ever used white vinegar or baking soda to clean out the grey and/or black tanks?

Nope, mainly because vinegar, baking soda, or hydrogen peroxide won't sanitize, but bleach will. Read this.

At room temperature only bleach will sanitize. Plus, you only need a 50ppm bleach solution (1/4 cup per 15 gal of holding tank capacity).

To sanitize like bleach but using vinegar or hydrogen peroxide, you'd have to heat the liquid to 130 degrees F and use full-strength solutions -- that's 15 gal vinegar or H2O2 per 15 gal holding tank capacity. $$$

Use bleach.

I agree I like my tanks to be clean and odor free before storing it for the winter. No they don't have to be sterile but for storing it IMHO the tanks 'need' to be clean. Getting all the paper bits and any stuck stuff off the walls and sensors etc IMHO, JMHO is important.

Filling the tank repeatedly with fresh water and dumping is what I did before putting it up for the winter.

On the last time I fill it up with water I add a couple of bottles of black tank chemicals. Not the ones that just add perfume the real chems that breaks down waste and eliminates odor. I use Campa-Chem.


Let that sit over night and then dump and I am done.

You can pick up a clear elbow sewer hose attachment and you can see how clean you are getting it. Mine usually took 3 fill and dumps the last fill being with the chems and the water ran perfectly clear. And BTW this makes sure your sewer hose is clean for storage also.

The real answer to your question really depends on what kind of a setup you have. If you have Sani-Flush (like I do) all you have to do is let it run for about 5 minutes, put a bit of chemical in and add a bit of water. (I was stunned that there was absolutely no odor when I had to change the seal on our toilet despite the fact or rig had been standing for a month. I did not even have to cap it while I was waiting for the parts to arrive from a mail order house.) Obviously, this method works.

I add some Thetford gray water treatment for the other tank. I have never had a problem with the tank making an odor. (The washing machine - yes - but that is another topic.)

This works for me.

I've only been doing it a short time, but I can attest after our last trip to the Calgon and Dawn treatment for the black tank. The grey tank should be fairly clean since you put soap in it when you wash your hands or take a shower. Unless you're throwing solids like food scraps (which you shouldn't be doing) in the sinks there shouldn't be any. As far as the black tank, when I dump it, I immediately mix a cup of Calgon and a cup of non-concentrated Dawn in a gallon jug of warm water and pour it down the toilet. So far so good....the tank seems to flush out very well at the end of the trip and no smell!! We also pour the soapy dish washing water down the toilet....(we wash in a pan in the kitchen sink instead of just rinsing it down the grey tank.)

I have never gone to that extreme.. back when I used to part time at the end of the season I'd use the GEO method (half a cup of Dawn Dishwashing liquid, original formula, half a cup Calgon Water softener, and about 1/6 to 1/3 tank of water, dump Drive for like an hour or more, dump when I got to my home dump station, tank would still read FULL (Of soap bubbles) but that is all.

I mean, what's going to happen to anything left in that tank? (Down into the hole in the ground and the septic system) so why bother.

I mean, what's going to happen to anything left in that tank? (Down into the hole in the ground and the septic system) so why bother.

Anything left/stuck in the tank and/or sensors will harden and it will not necessary come loose just by adding water and dumping. It will just attract more to stick to it.

And dawn, calgon, water softeners and all the mystical magical treatments for holding tanks leave a film/surfactants on sensors which is why so many people are always complaining their sensors don't work and everyone always reply that they never work anyway. :(

No you don't need a black tank you can eat off of, but paying attention to a few small details keeping it clean eliminates problems down the line. ALL my coaches I have owned had fully working sensors, never any sewer smells up to the day I sold them.