The Geo Method / Black and Gray Water Holding Tank

I noticed someone plagerized, and altered, my article on this forum a while back so I thought I'd post it properly. The link is to the original post on another site with supporting links. Permission is granted to copy and post the article UNMODIFIED, UNEDITED, AND WITH PROPER CREDIT. The low-life, belly crawling plagerist knows who he is.

The Original Geo Method Homepage and Blog

Black and Gray Water Holding Tank Maintenance

The Geo Method

By Charles Bruni
Renton, Washington

Everyone who owns an RV should be concerned with maintaining its wastewater tanks. Problems with wastewater tanks can and should be avoided. Wastewater tank repair is expensive. Due to health concerns, many service facilities will not work on wastewater tanks and lines until the tanks have been completely emptied and sanitized. This may be quite difficult when the tank(s) is in need of repair. So, common sense dictates that the tanks should be kept relatively clean at all times. Additionally, improper use of the wastewater tanks can lead to a build up of solid wastes, which in itself may cause the system to fail.

I've discovered very simple, effective, and inexpensive methods of maintaining my wastewater tanks in a relatively clean condition at all times. I developed these methods myself through my understanding of chemistry, physics, and biology with a smidgen of common sense thrown in for good measure. I also read my RV owner's manual. Although we are not full time RVers we use our fifth wheel camper at least one weekend a month. We never use public bathing and toilet facilities. In other words, our wastewater tanks are fairly heavily used. Since I've met a number of RVers who don't seem to know how to maintain their wastewater tanks I thought many RVers would find my tips useful. If you have not been maintaining your tanks I believe you will be pleasantly surprised the first time you employ these tips. I do these things and they work.

RVs are equipped with waste water HOLDING tanks; NOT septic tanks. Those holding tanks are nothing more than chamber pots. Chamber pots should be cleaned and sanitized after their contents are disposed of. The Geo Method is based on this fact.


When you are camping and your RV is connected to a sewer/septic intake, leave the drain valves closed until the tank is full and ready to dump. Dumping a full tank provides a sufficient quantity of water to flush solids from the tank. Leaving the drain valves open allows the water to drain off without flushing out solid waste. That solid waste will collect in the tank(s) and cause problems over time. If your tanks are not full when you are ready to dump them, fill them with fresh water first, and then dump them.


In other words, dump the black (commode) water tank first, then dump the galley tank, then dump the bathroom tank. This way you will be flushing out the dirtiest water with progressively cleaner water.


This stuff is amazing and it works. Buy a couple of boxes of powdered water softener at the grocery store. You'll find it located with or near the laundry detergent products. I prefer Calgon Water Softener because it dissolves quickly in water. Cheaper water softeners work just as well but dissolve more slowly. Dissolve two (2) cups of the water softener in a gallon of hot water. Then, pour the solution down the drain into the empty tank. Use two cups of softener for each wastewater tank in your RV. The tank's drain valve should be closed otherwise the softened water will just drain out. Then use the tank(s) normally until it is full and drain it normally. Add a cup of laundry detergent to the black (commode) water tank at the same time you add water softener. This will help clean the tank. The gray water tanks should already contain soap through normal use.

The water softener makes the solid waste let go from the sides of the tanks. If you've ever taken a shower in softened water you know that after rinsing the soap from your body your skin will feel slick. That's because all the soap rinses away with soft water. Softened water also prevents soap scum from sticking in the tub. Get the connection? With softened water gunk washes away instead of sticking. The same thing applies to your RV's wastewater tanks.

I use a clear plastic elbow connector to attach my sewer drain line to the wastewater outlet on my RV. It allows me to see how well things are progressing during a wastewater dump. Before I began using water softener regularly the black water tank's water was brown, the galley tank's water was brownish, and the bathroom tank's water was white. The first time I added water softener to the tanks the water coming from the black water tank was actually black (not brown) and the kitchen tank's water was also black (not brownish). The bathroom tank's water remained white. That told me that the water softener had actually done what I had intended for it to do and made solid waste, which had been stuck to the interior of the tanks, let go and drain away. I added water softener (and laundry detergent to the black tank) to all the wastewater tanks for the next few dumps to be certain all the solid waste possible had been cleaned away. The wastewater only appeared black on the initial treatment. I now add water softener and detergent to each tank once after every few dumps to maintain the system.

Too little water softener may not be of sufficient concentration to work effectively. Too much water softener will NOT hurt the tanks. So, if the amount you used didn't quite do the job, then use more the next time. Don't forget the laundry detergent.

Occasionally, I pour a half gallon of liquid bleach into each tank to deodorize, sanitize and disinfect them. I add the bleach when the tank is about half full, and then continue to use the tank normally until it is full and ready to dump. I no longer use the blue toilet chemical because it isn't necessary. I have no odors coming from my black water tank. The chlorine bleach kills the bacteria, which is primarily responsible for waste water tank odor. Generic brand liquid bleach is cheap and very effective.


Most fresh water contains sediment. Sediment will accumulate in your wastewater tanks and your fresh water lines. It also tends to discolor your sinks, tub/shower, and commode. I use the disposable type and have found that they eventually fill up and begin restricting the fresh water flow resulting in low pressure. That's how I know it's time to get a new filter. It works, it's cheap, it avoids problems, do it. When I fill my fresh water tank I attach the filter to the end of the hose and fill the tank with filtered water.


WATER, WATER, WATER - and more water! The Geo Method assumes you are hooked up to a plentiful clean water supply, and that you have access to a sewer. The water softener will make the gunk let go. That's only half the battle. After the gunk lets go it must then be flushed through the relatively small drain opening in the bottom of the tank. That takes water. Lots of water.

Will The Geo Method work even if most of the time I'm NOT hooked up to water and sewer? YES! Just use common sense. If you dry camp ninety percent of the time just keep water softener and detergent in your tanks (especially the black tank) while you're dry camping. This will keep gunk from sticking to the tanks. When you are hooked up to sewer and water take the opportunity to fill the tanks with fresh water and flush the tanks. Keep flushing them until the water runs clear. I know it works because I've done it.

Never put regular toilet tissue in your RV's black tank. Only use toilet tissue which is approved for RV and/or septic tank use. Regular toilet tissue may eventually dissolve, but not before causing a clog in your black tank.

I believe occasionally traveling with partially filled wastewater tanks that contain softened water promotes cleaning by agitating the water. The same goes for chlorine bleach.

I believe this process works faster and more efficiently during warm weather. However, I know it works well even during cool/cold weather.

I believe the process works best the longer the water softener remains in the tanks. So, I don't add water softener during periods of heavy wastewater generation. I wait until I know we won't be generating wastewater quickly so that the softened water remains in the tanks for several days before dumping.

If you have an older RV you may have to use water softener and detergent several times initially to completely clean the tanks of residue.

I add a small amount of chlorine bleach to the fresh water tank twice a year to disinfect and sanitize the fresh water tank and fresh water lines. A weak chlorine bleach solution will not hurt you. However, it certainly makes the water taste bad. When we have chlorine in the fresh water system we use bottled water for drinking and cooking until the chlorine is gone. YES, we drink the filtered water that we have in the fresh water tank. NO, it has never tasted funny or caused any problems.

No, I do NOT do the ice cube thing. The Geo Method works just fine without ice cubes.

My tanks are plastic and my pipes are PVC.

Don't be afraid to use your tanks. Just use common sense about their care and maintenance.

These tips are inexpensive to do. Some of them don't cost anything. You have nothing to lose in trying them and I encourage you to do so. I actually feel a certain amount of pride in the condition and cleanliness of both my waste and fresh water systems. Naturally, these tips make dumping a much more pleasant and sanitary procedure.

If you have odors in any of your water systems these procedures should eliminate them. Odors indicate a sanitary problem and degrade the enjoyment you derive from your RV.

When my RV is parked and not in use I place stoppers in the sink and tub drains. This forces the wastewater tanks to vent through the vent pipes to the outside instead of through the drains into the RV. Water evaporates. Once the drain traps dry out during periods of non-use, nothing is there to prevent gasses (odor) from venting into the camper. Use stoppers when your RV is stored.

Copyright(c)Charles Bruni

Please consider printing this information and posting it on bulletin boards in RV parks and campgrounds you visit. Fellow RVers will benefit from your consideration.
The Geo Method / Black and Gray Water Holding Tank

Read your post and it looks real good, so I copied it and pasted it the general RV'ing section.

The Geo Method / Black and Gray Water Holding Tank


Please stop following me around the internet from forum to forum. If you don't like The Geo Method the solution is simple; don't use it. People who try The Geo Method like it because it works and it's spreading rapidly through the RV community. Get over it.
The Geo Method / Black and Gray Water Holding Tank

Having lived in a house with a septic system I have a problem with the amount of bleach being dumped into the system when you empty your tanks.If everyone uses this system ,all campgrounds will have system failure and noone will allow dumping.I know you don't consider system failure your problem cause you're moving on.If someone else got to the next destination before you you will be out of luck.
The Geo Method / Black and Gray Water Holding Tank

quote:I've discovered very simple, effective, and inexpensive methods of maintaining my wastewater tanks in a relatively clean condition at all times. I developed these methods myself through my understanding of chemistry, physics, and biology with a smidgen of common sense thrown in for good measure.

Once again Geo, thanks for the great method to clean my RV holding tanks. As I said in another forum,
my husband and I went to Canada and back from Illinois. It was a month long trip so our tanks got a full workout since we never use public facilities. This method worked fantastic! I'm known in my family for my 'super' nose. It's a curse when the holding tank is stinky, lol. However, by using this method I was spared! The tanks are cleaner than ever and I can tell the difference. Thanks again for this simple, yet effective treatment program. :)
The Geo Method / Black and Gray Water Holding Tank

I'm not the only one who knows that the Eco-Kook Luddites are poorly educated and illinformed. Thanks Snowbird.

Cut and paste from original post:

From an article on the manufacture of bleach and it's uses...

Not happy with the title of "World's Most Popular Germ-Killer", bleach is also used in great quantities by industries worldwide. An enormous commercial market for industrial bleach exists, where it used for wastewater treatment, drinking water disinfection and textile and paper manufacturing. It is used to treat sewage and industrial wastes to reduce odors and increase digesting efficiency. Hypochlorite bleach neutralizes sulfer hydrogen gas (SH) and ammonia (NH3). It detoxifies cyanide baths in metal finishing industries and treats cyanide effluents created by gold mining. Bleach is also used to recover precious metals from manufacturing solutions. Air scrubbing systems use bleach to destroy pathogens and neutralize gases. Without bleach, much of the food processing done in North America would not be possible. It is used to clean dairy equipment and food processing equipment, in fruit, vegetable, mushroom, hog, beef, poultry, fish and maple syrup processing. One of the first uses for commercial uses bleach was its use as a cotton whitener. It remains one of the most important chemicals used in textile manufacturing. Bleach is also used to whiten paper, soap, straw, wood and many other organic products.

I am being a little more serious this time, but for the love of Peteâ„¢ did any of you people pay attention in your high school chemistry classes? This is so basic (Pun intended although I am sure it will fly well over most of the heads in here.), but you would have to have a few gallons of a much stronger concentration of bleach than the 5.25% you're buying in the local Piggly Wiggly. Let's follow this up by topping off the tank with the strongest ammonia you can get your hands we can get the sort of vigorous chemical reaction that you junior chemist's are thinking about.

We are talking about 1 or 2 cups of bleach in a 40 gallon tank...let's cut it in half and call it a 20 gallon tank....let's get really crazy and dump a gallon of bleach in there.....I am still not worried. Let's pretend I use 2 cups of 5.25% bleach in my holding tank each time I dump. I am a lazy idiot so I won't even bother putting a couple of gallons of water in my holding tank for good measure. (Another one of those danged ole puns....) I still don't have much to worry about and I would have to do it over and over to have an appreciable affect on the gate seal. Even if the gate seal goes prematurely, like in a few years or so....I can rebuild it for a couple of bucks and 5 minutes of my time. Ooooooh, big deal.

This misinformation is annoying. People who have no clue what they are talking about spewing some trash they have heard 4th hand really peeve me. I don't care if your uncle's cousin's third ex-wife had it happen to her, it's not true. I don't know everything, I don't even know that much, but I did pay attention in school and I can look up most anything I need to know in minutes using this new fangled Internet thingy. Here's another suggestion for you; I would highly recommend that you look at multiple sources for your information, especially if there is potential for injury to you or others. Sometimes I wish these bogus stories were true, there would be far fewer people driving the highways without functioning turn signals.

Much of the information shared on this forum is extremely useful and is a great service to those who need it the most. A minor problem exists in that some of the information is wrong. A huge problem exists in that some of the information is not only wrong, but dangerous. I would like to personally thank those who have spent there own time and money resolving an issue and then sharing that information with the rest of us. I have saved much time and frustration reading these boards, but I know well enough that not everything is correct and I need to use my own common sense with some issues. Other issues require that I research the problem in greater detail before making a decision. Adding a cup of bleach to my holding tank doesn't take rocket science (another obscure pun) to realize that it will cause no harm to myself or my tank. One dollar worth of bleach is much better for your tank and the enviroment than $11 worth of blue crap. (He did it again, those danged old puns.)
The Geo Method / Black and Gray Water Holding Tank

Well ****!!! This little topic turned into a real urination contest now didn't it?? Wonder why?

I may try this method, my MH is brand new and nobodys has used any of the holding tanks yet. But this sounds as good as any method I ever heard of. Besides some protest to loudly and this makes me wonder.


DL Rupper

Senior Member
Re: The Geo Method / Black and Gray Water Holding Tank

Hey Snowbird, does this mean we are off and running again on this subject. I love it. Lordy, Lordy, Lordy. Let the fun begin. :evil: :laugh: :laugh: :laugh:
Re: The Geo Method / Black and Gray Water Holding Tank

DL Rupper - 3/1/2007 3:42 PM Hey Snowbird, does this mean we are off and running again on this subject. I love it. Lordy, Lordy, Lordy. Let the fun begin. :evil: :laugh: :laugh: :laugh:
Ha ha. Actually I was curious because I clicked on here and went to read the last post and there wasn't anything after the first page. I guess they deleted all the good stuff, lol. :angry:


Senior Member
Re: The Geo Method / Black and Gray Water Holding Tank

Everyone is entitled to an opinion. But is a pissing contest necessary? A lot of people join these forums to learn from others and others ideas. Not to read about how others dont care for other people or their opinions. I think it would be better if people who have harsh feeling towards other people keep it to themselves and off the boards. If they cant I am sure that if enough people complained about it they could very easily be removed whether they are new or have been here since 2001. So please lets all get back to the purpose of this forum and try to get along.
One mans opinion!!!!!


Senior Member
Re: The Geo Method / Black and Gray Water Holding Tank

Sorry it wasnt meant as a threat. I was just tired of reading the garbage. Thought maybe it would make people think before going swimming in the black water. LOL
Re: The Geo Method / Black and Gray Water Holding Tank

utah----there are all kinds of threads on this and any forum. bantering livens things up on some threads from time to time. if you don't like that then don't read them. there is no rule on this or any other forum that says you have to read stuff you don't like.


Senior Member
Re: The Geo Method / Black and Gray Water Holding Tank

Ben, do you know if a thread is good or bad without reading it? If you can tell us how to do that it would probably make may people happy.