The Extreme RV Holding Tank Cleaner by Happy Campers is just that - Extreme! For use to totally clean RV & Marine black or gray waste holding tanks. This is NOT a regular maintenance treatment, this product is designed to totally clean RV and mar
The Extreme RV Holding Tank Cleaner by Happy Campers is just that - Extreme! For use to totally clean RV & Marine black or gray waste holding tanks. This is NOT a regular maintenance treatment, this product is designed to totally clean RV and marine holding tanks when you know you've got a problem. We highly recommend that you watch what comes out of your holding tank even if you thought it was fairly clean & you'll be surprised. USES: 1) Thoroughly Cleans RV holding tanks 2) Cleans poor working sensors. 3) Softens & removes solid buildup. 4) You just bought your RV; want to super clean the tanks for a fresh start. 5) A great product for an annual clean out, especially when winterizing. Recommended for use in 30-60 gallon tanks. 100% Satisfaction Guaranteed! DIRECTIONS: 1. Dump and Thoroughly Rinse Holding Tank 2. Put 3 to 4 gallons of hot water in a bucket, then add and mix in the entire container of Extreme Cleaner. Mix until fully dissolved. 3. Pour into toile and flush. OR Pour down sink for gray tank. 4. Add 5-7 more gallons of water (if stationery completely fill tank) 5. For best results drive your RV or trailer on a good windy road to aggressively agitate and clean tank. 6. As soon as you are 'hooked up' dump the tank and rinse well. Much like clothes in a washing machine, rinsing & agitation does most of the work, EXTREME CLEANER simply softens & helps dissolve sludge & crud in holding tanks. Use on-board or flexible down-the-toilet rinser for best results. If your trailer/RV is not mobile: Fill your holding tank as full as possible and add the entire container for treatment following step 2 above. Leave in your holding tank 48-72 hours before dumping. Note: Holding tank sensors are historically temperamental, heavy cleaning will usually (but not always) restore scum crusted sensors. Stationary units require more rinsing with less success. Will not dissolve wipes or fix broken or corroded probes.*This product is not intended to be a regular holding tank treatment or deodorant.
What Our Customers Say
January 17, 2026
Absolutely no complaints!
I'm happy with this. And it works so very, so great.
- Math L..
January 17, 2026
Absolutely no complaints!
It's a very good, exceptionally and so well-made product.
- Gwawl B..
January 17, 2026
Absolutely no complaints!
An excellent choice. It works really, really, really great.
- Rhiannon W..
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