RV Maintenance Tip #1 – Tank Cleaning and Maintenance

No matter how long you’ve owned your RV, its inevitable that you’ll run into a chore that is just plain CRAPPY; flushing and cleaning your sewer tanks! We’ve compiled a step-by-step guide of how we properly care for our black and gray tanks (sewage system) that will mitigate costly repairs down the road.

RV’s generally have three different holding tanks… 

White Tank – Fresh potable water

Gray Tank – Shower and sink dirty water

Black Tank – Toilet water and contents

Each tank has electronic sensors that indicates available capacity on our panel inside our RV.  Most often though, debris from waste collects on these sensors giving false indications.  To alleviate frustrations of not knowing how close those tanks are to capacity, it’s a good idea to clean your tanks thoroughly to rid that debris (sludge, paper, calcium, etc.) so readings will be accurate as part of our regular tank and sewage system maintenance.


Here’s what we do:

  • Always wait until tanks are two-thirds full before dumping.  When hooked up to sewer, we’ve learned to keep both gray and black tank valves closed until dump time as to not allow any waste to dry out or solidify.  (Note: there’s controversy of whether to keep the gray tank open vs. closed.  ‘We’ keep ours closed based on professional advice).
  • On ‘Dump Days’, first and foremost, Don your doctor gloves (rubber/latex gloves).  Dump BLACK tank first and flush your GRAY tank second as it will clean black tank ‘crap’ out of your sewer hose.
  • Use as much water as possible and back-flush (ours is factory installed).  We do this two or three times. If you don’t have a factory installed back-flush system, you can easily install aftermarket systems.  The end result you want is the water that flushes from your tanks to be clear.
  • Close BOTH Black and Gray tank valves and keep them closed until our next ‘Dump Day’.
  • After we’ve thoroughly flushed our systems two or three times, we then dump an ‘environmentally safe’ GEO Method mixture of 1 Cup Calgon Water Softener (cleans scum and prevents hard water deposits on the sensors and breaks down water surface tension) and 1 Cup Borax Powder into a 5-gallon bucket of hot water to disolve and then dump it down your toilet and leave it.  This insures we won’t have ‘piling’ in the bottom of the tank.


  • Just remember, in the black tank WATER IS YOUR FRIEND!


Sounds simple enough, right?

While we were attending the Heartland Owners Club North American Rally in Goshen, Indiana this past June (2017), we made an appointment with Jim Tome, President of Kleen Tank to give Liberty a colonoscopy and get some professional guidance on how to keep our sewage system and tanks in top notch condition.

BTW, this is ‘Jim’…he was our Kleen Tank guy…and he’s the President (of the company)!  Good thing he has a sense of humor!  I guess you need that for this kind of job being an RV Proctologist!

Before going on explaining his procedure…

Here’s what Kleen Tank recommends for tank maintenance:

  • BEFORE LEAVING FOR YOUR TRIP:  Fill gray and black water holding tanks about 1/3 full of fresh water. The sloshing motion of your moving RV combined with the water in the tanks will help break down solids, gently clean the tanks and help with the overall health and maintenance of your RV’s waste holding tanks
  • DURING YOUR TRIP OR AS YOU USE YOUR RV: Keep both tanks closed (as we also mentioned above) always.  Your tanks’ sensor panel should read 2/3’s to full before dumping.  If they don’t and you need to dump, top off both tanks with fresh water for an accelerated exit flow.  When you leave the campground, dump the tanks and again, fill each 1/3 full of fresh water for your trip home or next destination.  This will help keep your tanks lubricated and the sloshing will minimize maintenance needs.
  • AFTER YOUR TRIP:  Top off both tanks with fresh water and dump before storing.  Be sure to winterize (if applicable) and add a lubricating antifreeze to tanks before storing long-term.  This is a critical maintenance need.
Now, how Kleen Tank‘s cleaning procedure works:
Using our exclusive hydrojetting technology, Kleen Tank, an authorized All Pro Water Flow dealer, gets your RV’s waste holding tanks clean — from the inside — without damaging chemicals, messing up your campsite, or upsetting your neighbors. Whether it’s a clogged RV toilet, a slow draining system, or just annual maintenance on your RV’s waste system, Kleen Tank is fast, economical, and safe for the environment — and your RV.

We’ve mentioned in our protocol the GEO Method that we use, this is Kleen Tank’s recipe for keeping gray and black tanks clean (he gave us a sample to try):

Mix 40 ounces of Pine-Sol with enough water to just about fill a gallon jug. Top off with a half cup of Calgon Bath Beads. Use eight ounces in each tank (or more in especially hot weather or if your tanks will be filling up slowly over time).  NOTE:  DO NOT USE THIS IN YOUR FRESH WATER TANK!
Now…onto the ‘procedure’!!
  • The first thing he did was empty both the black and gray tanks.
  • He back-flushed the black tank 3x and gray tank 2x thoroughly; filling the tanks and then doing tornado flushes.
  • He then, inserted a tube-like hydrojet hose with a thin nozzle on the end up into the plumbing connection and into the tank and started power flushing to clean not only the pipes and tanks, but the sensors also.  Even our tank being less than 2 years old, lots of ‘crap’ came out (I know, TMI).  He did this for about 15 minutes wiggling it back and forth to get every bend and crevice.


  • He flushed the black tank again using a tornado method.  YAY!  No more chunks of junk! Clear water!
  • He then moved onto cleaning our fresh water.  If you notice, he changed his gloves. Never use the same gloves that you use on sewer vs. fresh water.
  • He removed the panel where the ‘anode’ goes.
  • He removed and inspected the anode pictured above which was in good condition because Captain Dan just replaced our anode only a few months ago. BTW, you should change your anode according to use, full-time/part-time status and locations where you’ve parked.  Some places have higher calcification and mineral buildups.  Inspect them often.  Dan changes ours about once a year.
  • Once he removed the anode, he carefully drained the hot water tank (it was scalding hot!).
  • Jim then attached this flexible nozzle that inserted into where the anode goes.  We bought a nozzle at the Rally vendor fair at his table for about $15.  You can find them on Amazon; called a ‘RV Water Heater Wand’.


We thought Dan did a good job flushing it out when he changed the anode out but guess what? This is just a fraction of what came out, I guess not so much.  Look under the wand to see the calcified chunks.  These impede the proper function of your water heater if left in there.  So, as you see, this wand will definitely help in future flushings.  Get one!  Since we already have an on board water filtration system, ours wasn’t ‘that bad’.  If your RV does not, consider more frequent cleanings.

We put a penny in the strainer to show you size comparison of the chunks of calcification that came out.  You can click on the photo below and enlarge it.


After Jim completed the whole process, he told us that 5th wheels are easier and roomier to work with however, there are more twists and turns of the pipes.  Travel Trailers, on the other hand, are easiest because the pipes are straighter and shorter.

The complete Kleen Tank process took approximately 2 hours. The cost to have the gray and black tanks cleaned and water heater cleaned/flushed was $200 (Rally/Show price).  Normally, it’s about $250-300.
Did we ‘need’ to do the complete process on such a new coach?  Probably not however, since we are full-timers and this is our home, we take extreme care of it.  If we didn’t, this chore could turn into a really crappier chore costly issue and we certainly don’t want THAT!

2 Replies to “RV Maintenance Tip #1 – Tank Cleaning and Maintenance”

  1. Hi Guys. Thanks for the informative post. One question, you mention your method for cleaning out your BW tank (1 Cup Calgon Water Softener and 1 Cup Borax Powder) and Kleen Tank's GEO method (Pine-Sol with a half cup of Calgon Bath). Do both recipes accomplish the same thing? Also, you don't mention when you add the Kleen Tank slush to your system. Is this added just before leaving camp? Thanks!

    1. Jonah, thank for reading and paying attention to that. You can use one of the other. We use ours after we empty our tanks and flush really well.

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