Heavy-Duty RV Holding Tank Cleaner for Black & Gray Tanks
When regular treatments aren’t enough, Happy Campers Extreme RV Holding Tank Cleaner provides a one-time deep cleaning process designed to loosen stubborn buildup, restore tank sensors, and remove the sources of persistent odors in both black and gray tanks.
Why Choose Our RV Holding Tank Deep Clean & Reset Treatment?
- Heavy-duty, one-time deep cleaning treatment
- Loosens compacted waste and sensor-fouling residue
- Helps restore function to dirty tank sensors
- Compatible with black and gray holding tanks
- Safe for RV plumbing and campground dump systems
- Please Take a Look at our Total Tank Reset Guide
How to Use:
- Dump and thoroughly rinse your RV holding tank
- Mix the entire container of Extreme Cleaner into 3–4 gallons of hot water in a bucket and stir until fully dissolved
- Pour the solution into the toilet (for black tank) or down the sink (for gray tank)
- Add an additional 5–7 gallons of water into the tank; if parked, fill the tank as full as possible
- Drive your RV on winding or uneven roads to help agitate and loosen buildup
- Once you reach your destination, dump and rinse the tank thoroughly
Important Notes:
Agitation (via driving) and thorough rinsing are key to results. Extreme Cleaner works by loosening and dissolving accumulated residue, while water flow and movement complete the cleaning process.
For non-mobile RVs, fill the tank as full as possible and allow the solution to soak for 48–72 hours before dumping. Use a tank rinser for best results.
Sensor notice: While many sensors regain proper readings after heavy cleaning, results may vary depending on buildup thickness or probe condition. This product will not dissolve wipes or repair broken or corroded probes.
Looking for ongoing maintenance after a deep clean? Try our daily-use odor control treatments next.
This Is NOT a Regular Maintenance Odor Control Treatment
Extreme Cleaner is designed for situations where buildup and residue have accumulated beyond what routine treatments can address. It focuses on deep cleaning through dissolution, soaking, and flushing — not daily odor maintenance.
We recommend observing what exits your holding tank during the dump process, even if the tank appeared clean beforehand — the results often reveal hidden buildup.
The Extreme RV Holding Tank Cleaner Is Easy to Use and Can Be Used For:
USES:
1) Thoroughly cleaning RV holding tanks
2) Improving sensor accuracy by removing residue buildup
3) Softening and removing compacted waste deposits
4) Resetting tanks after purchasing a used RV
5) Annual or seasonal deep cleaning, including winterization prep
*Recommended for use in 30–60 gallon tanks.
Videos Hide Videos Show Videos
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Happy Campers Extreme RV Black Tank Cleaner - What it Does and How to Use it for Best Results
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Satisfied with the effectiveness of the product.
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Have not used
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Bought the Extreme cleaner for our grey tank because it worked 'extremely well' in our black tank.
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I purchased this to get my sensors in the black holding tank to work but it didn't help. However the water that came out was brown whereas it had been clear prior to using this product so evidently it did clean the tank but not affect the sensors
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We have tried every product you can think of to clean holding tanks and we have been trying for 20 years EXTREME is hands down is the best product we have found and I guess that's why it's been hard to get
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Absolutely positively the best tank cleaner ever made. After many other attempts to clean and deodorize my black tank HappY Campers Extreme did it in one try. I am now following up with with regular Happy Campers and have not had a single issue. My sensors actually work now too. I strongly urge you to use Extreme to get it cleaned right the first time.
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This is the second time I have used this product and I am very happy with it. Since I likely let too much "material" build up during the camping season, it is nice to have this product at the beginning and end of the season to do a thorough cleaning. Having a clean tank allows the Happy Camper treatment that they sell to do a great job keeping things clean. I like to use this product once a year to keep my black tank working well.
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I was dealing with a possible huge headache with my black tank as well as the usual issue of tank sensor problems. I used the Happy Campers Extreme product and then the regular Happy Campers. The black tank now runs clear and the sensors work! Thank you for a tremendous product!
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This stuff works amazingly well if you use it according to the directions it will clean out your tanks and get them ice cream is new.