Walex Commando RV Black Holding Tank & Sensor Cleaner - Eliminates Waste & Paper Buildup, Restores Sensor Function, Lubricates Valves & Seals, Advanced Enzyme Formula; Dissolvable Packets, 4 Count[Amazon-developed Certification] Compact by Design

Work GREAT for unclogging black water tank issues.

I bought a Rv that sat for 10 years without use. The black tank was full. I did flush tank a few times but was having problems with the sensor. I tried different brands but truthfully i am amazed and will definitely will be a repeat customer. I let the tank set for a weak going by directions and i am extremely satisfied with this product. My sensor now work right and i can confidently flush my black tank knowing its empty and clean correctly

This product doesn’t guarantee to fix the RV sensors so with that said I can’t fault the product, we just might need new tank sensors. The product did do an excellent job cleaning the tanks and has a pleasant scent that is not overpowering. I wish it had fixed our sensors!

Busts up hard chunks. Soak 24 hrs in FULL tank. Best if used after dumping. Refill with water and treatment

Why did you pick this product vs others?:I picked this product because of other customers feedback. I put it in my black tank as described for 36 hours before draining. My sensors starting working properly again reading empty instead of 1/3 to 2/3 all the time. I will keep a bag of these amazing cleaners to use periodically to keep the buildup off the sensors and eliminate odor.

We always had trouble w/the accuracy of our black water holding tank in our RV. It would read empty after flushing it, then on arriving home it would read 1/3 full. We heard that stuff can get attached to the sensors inside the tank and no matter how we good we flushed it out it would never read accurately. We decided to try this product and my husband let it sit in the tank for several days. Immediately after flushing it all out the tank read empty and stayed on empty. We thought this fixed the problem. Well.... it did but not for long. The next time we camped we ran into the same problem, reading empty after the flush at the campground, but then reading 1/3 full after we arrived home. My husband did another application of this product and it fixed the problem again, and the tank read empty and stayed reading empty. So.... we have decided that this product does what it is supposed to do as long as you use it after every use. But this could get a little expensive. The company sends you 4 packets (a years supply), so their intent is not for it to be used after every trip. Don't think we will buy it again.

We had a tank sensor stuck on full. Used these and filled the tank. Drove around a little and drained the tank. God as New these work fantastic Highly recommend them

Works great when used per directions.