Archive for April, 2010

As I said in my previous post this topic usually generates lost of comments.  The comment below come form friend and fellow RVer.  Since his comments are extensive I thought they warranted there own post.:

While I never use chemicals, I’ve never said it would not work.  I just think there are better ways.  On the down side, cleaning with chemicals is very slow and expensive.  It will take several to many applications.

I am a more pro-active person.  When I have a problem, I solve it.  While I have never had this problem due to my actions, I once bought an RV that did and I have helped several people who had this problem.  I solve the problem this way:

1. My first consideration is, how much time do I have?  If the RV is parked for several weeks you can attack the problem in stages.  If they are living in it, can they use the camp facilities?
2. Next in importance, is the RV hooked up to a sewer system?  It is impossible to clean the RV’s black tank if it is not hooked up to a sewer.
3. Will water drain freely from the tank, or has the pyramid covered the drain?  As long as I can get a trickle of water I know I can attack the problem with water.  If the drain is plugged, you have to be very careful not to over fill the black tank.
4. If I have drainage and I have several weeks, I will put in a cup of Rid-X, fill the tank with water and let it sit for a week.  This will soften the mound and make it easier to chip away at.  I am not attempting to completely clear the tank here, but to make the mound more amenable to reduction.
5. If I do not have drainage that becomes priority one.  In this case I go directly to work with a long toilet spray wand.  I must attain some drainage.  I jab the wand down into the mound as far as I can and then turn it on.  I use low pressure to prevent filling the tank.  Once I have a little drainage, I will work in stages, never letting the tank fill.
6. If time is of the essence, I go right to work with the wand.  It never takes longer than a few hours, but it is hard work.  You are in and out of the RV, filling and draining the tank, opening and closing the valve.
7. My favorite method is to put the spray wand into the top of the mound and then press down at an angle, then I turn the water on.  The easiest path for for the water is back up the hole created by the wand.  If you go straight down, the ugly water may spray back in your face.  I have plugged the hole in the bottom of the toilet with a rag to prevent spray-back.  I try to destroy the mound from the inside out.  The object is to saturate the mound with water to help soften it.  Just keep the wand moving.
8. From here on it is just wand on, wand off, valve closed, valve open.  If I have time, I like to fill the tank and let it sit for several hours or overnight.
9. When I think I am done, I fill the tank half way, put in ten pounds of crushed ice and go for a drive.  Then I fill and drain several more times.

As you suggested, I leave the black tank valve closed until it is around 3/4 full.  And, I always use Rid-X.  It generally takes me two weeks to fill that tank.  I use a variety of my black tank, camp facilities and facilities I come across during the day.  The Rid-X, for want of a better word, emulsifies the contents of the tank.  It is a simple bacteria that breaks down lumps and clumps.  If I were cleaning the tank more often than once a week, I would not bother with the Rid-X.  It works best when it has time.

Going forward I will not own an RV that does not have a built in tank spray system.  It really helps.  However, if you generally leave your black tank valve open, you will have a problem.

I hope this helps.

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The tip below was inspired by a discussion on the RV Basics Yahoo group. A member of the group wrote that he was advised to keep his RV black tank valve open during the winter to avoid freezing. The result of following that ‘tip’ was a clogged black tank.

I have to say that while I invaribly believe what I write… I don’t offer tips I wouldn’t follow myself. Several members of the group have passionately disagreed with me. I offer my opinions as food for thought. It’s up to you to decide what will work for you. Please feel free to add your comments below.

While I believe the mechanical methods: broomstick or awning wand down the toilet, toilet flush wands, back flushing, etc. for clearing a clogged black tank are usually the most efficient and cheapest, I see no problem with using chemicals if one wants to do so.

I’ve never agreed with those who caution against using Drano, Liquid Plumber, etc. in RV plumbing because it will harm something in the system.

Here’s why.

RVs are plumbed using mostly the same plastic piping and fittings that houses are plumbed with. Even the ‘special RV’ plumbing fittings and parts are made from the same plastics. So if household plumbing chemicals are safe to use in household plumbing I cannot see why they are not safe for RV plumbing.

The only ‘seals’ in my RV’s plumbing are in the dump valves and they appear to be rubber. I have not found any evidence that plumbing chemicals have a harmful affect on rubber. Even if there is, I can’t believe that short term exposure during the unclogging of a black tank would be a problem. Rubber is pretty tough stuff and will be rinsed well with water after the project is complete.

As for these chemicals killing off waste digesting micro organisms, the Drano company website says their products are not harmful to septic systems. Okay, so it was the company saying that. I have to believe the FTC or an enterprising lawyer would have taken action already if it could be proven otherwise.

Keep in mind we are discussing how to clear a clogged black tank. We’re not talking about using these sludge busting chemicals on a regular basis. Once the tank is cleared, rinsed and ready for service again you can introduce new enzymes and bacteria back into the tank if you want to.

Then again, I don’t consider my black tank to be a mini septic system. It is simply a holding tank to store the waste until it can be properly disposed of. Therefore I see no value in costly enzyme tank additives.

To help prevent future clogs always keep the black tank valve closed. Don’t empty the tank until it is at least 2/3 full. If it isn’t 2/3 full, add water until it is. After each dump and rinse, close the valve and add enough water to cover the bottom of the tank. The first few times you flush solids use extra water to flush the solids away from under the toilet. As the tank fills you can use less water to flush to increase the time between dumps.

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