Thorough research of this problem led Preston to develop a special nozzle for cleaning holding tanks with water under high pressure. This system cleans the inside of RV holding tanks without the use of chemicals. It's a green cleaning system. We decided to have this service performed while at the rally.
BACKGROUND:Most RVs have 3 tanks. One for Fresh Water that supplies the sinks and shower and toilet, one called the GREY tank that has the waste water from the shower and sinks and one called the BLACK tank that holds the toilet waste.
All RVs have a gauge that tells the user how much fluid is in the tanks. Most of the gauges have sensors that protrude about 1/8" into the tank. When fluid touches the sensor it shorts the circuit and that makes the gauge read that level. There is usually a sensor for FULL, 2/3, and 1/3. When none are shorted the gauge reads EMPTY. There are also sensors that are mounted by adhesive to the outside of the tanks. These sensors read the fluid level through the plastic tank. (see our previous post on plumbing and the SeeLevel system we have installed).
Both GREY and BLACK tank sensors often become unreliable, especially the BLACK tank. This is because the contents of the tank, over time, have umm, material adhering to the walls. Internal sensors get covered by the ummm, material so the sensors think they are covered by fluid and will read FULL when it fact the tank may be EMPTY. External sensors usually do better but can also read badly if the material coats all or part of the tank wall. OUR RV has SeeLevel external sensors and recently they would read full when the tank was between 6% and 50%. Less than 6% the sensor read OK and over 50% it read OK. This indicated to me that the tank had material heavily coating the lower half of the tank. Almost ALL RV's do or will have bad sensor readings at least in the BLACK tank.
All Pro Water Flow to the rescue!!
Preston Hall, founder of All Pro Water-Flow was in attendance at the rally and put on 2 seminars. We missed the first one, got the cleaning done and then went to the second seminar. We didn't really need to be sold on the service, we already knew we wanted to get it done, but wanted to hear his presentation.
The cable connected to the water pressure pump has a nozzle on the end that is patented by Preston Hall, the founder of All Pro Water-Flow. It sprays water back towards the user after it is inserted into the tank. This makes it crawl or self propel itself into the tank and blows water backwards against the tank wall where the sensors are. As Preston fed the cable in he would work it in and out over and over again, twisting it around so it sprayed all over the inside of the tank. I had flushed the tanks thoroughly before we had this done, but he was able to get quite a bit more out. He had a short clear plastic extension on the tank's outlet pipe so you could see how dirty the water was. He flushed the grey and black tanks about 20 minutes each. Calcium builds up on the inside walls of the grey tank. Preston's hydro-cleaning service breaks up the calcium and removes it. The same cleaning process breaks up sludge and material in the black tank that covers the sensors. I later filled the black tank all the way to 100% and got sensor readings all the way up so the cleaning obviously worked.
Preston gave us some tips on keeping the holding tanks clean. He suggested NOT using any chemicals for "breaking up" the waste. Many RV toilet chemicals state that they break up waste. He says that those chemicals are not needed and may actually cause more sludge to form. He had a recipe for a treatment that is home made so much cheaper than the RV specific chemicals. The recipe follows:
in a 1 gallon jug..
add 48 ounces of Pine-sol
add water to almost full in the gallon jug
add 1/2 cup Calgon Bath Oil Beads
Shake it up, it turns light green
add 8 ounces of the mix to each tank after each dump
The Calgon makes the tank walls very slick and will help keep material from sticking to them.
The Pine-Sol has fragrance for odor control and pine oil to lubricate the valves.
The whole process was easy and pretty fast. NOW we'll see how long the tank sensors read correctly.
Here are some photos of the process.......... Enjoy our colonoscopy!