Black Tank Guidelines

  • 3 min read

Read series from the beginning


The Unique Method offers a well-calculated mix of healthy care habits that will improve the condition of your holding tanks no matter what kind of treatment product you decide to use, the type of camping you’re doing, or what kind of weather arises. In this article, we’ll examine the actual steps for maintaining trouble-free black water tanks. We have provided a brief amount of detail in the steps below, but will be discussing some of these details in more depth in later articles. Since we recommend using a high-quality treatment product with The Unique Method and our products were designed with The Unique Method in mind, we will be using Unique Camping + Marine products as examples while walking through the steps. The best way to get the most success out of using the method is to combine it with the products for which it was created. Follow the guidelines below as closely as possible, and you will easily avoid clogs, odors, and misreading sensors.

Note: RVers with Class B RVs or others with smaller sized holding tanks can still apply our recommendations, with adjustments for a smaller tank.


  1. Always keep your black tank valve closed, unless you’re dumping a full tank.
  2. Always treat your black holding tank with a high-quality bacteria and enzyme treatment (such as Unique RV Digest-It) after each dump.
  3. Always keep several inches of water in your toilet bowl (unless driving), which creates a water barrier, preventing foul smells from seeping into your RV living space.
  4. Always fill your toilet bowl with water before you use the toilet; this will help solid waste flow easily down the line and deter any trapped odors from rising during the flush.
  5. Use ample amounts of water each time you flush your toilet.

    Hold down the flush mechanism for ten full seconds each time you flush your toilet which will continually add water to your black tank.

  6. Try to keep your tank temperatures below 85 degrees.

    When temps go up, so do odors. If you begin to get a smell, simply use more water with each flush. You may also need to add another treatment dose and dump more often (if possible).

  7. Dump your tanks every 3-5 days for optimum odor control.

    If you extend the time between dumps (like when dry camping/boondocking), treat your tanks every 4 days with your bacteria and enzyme treatment and keep plenty of water in your holding tank.

  8. Flush your holding tank for 20-30 minutes with a built-in tank-rinser, backflusher, or rinsing wand every 3-5 dumps (for hook-up campers) or after returning from each trip(dry campers/boondockers).

    Waste (regardless of the tank treatment) will collect and accumulate in the low spots and crevices of your holding tank; rinsing helps knock down those clingy stowaways.

  9. Avoid cleaning your toilets with chemicals or bleach.

    Use RV toilet cleaners that will increase beneficial bacteria, like Unique RV Toilet Cleaner + Holding Tank Enhancer.

  10. Perform a deep clean on your black tank twice per year (season beginning and end for weekend campers) or every 5-10 dumps (for full-time RVers).

    Unique Tank Cleaner is specially designed for deep cleaning your black tank. This will remove waste from the tank walls and floor, remove debris that may have collected on the sensors, and lubricate your valves and seals. Refer to our guide on Deep Cleaning RV Wastewater Holding Tanks.

  11. Never store your RV with waste in the tanks.

    Storing your RV with waste in the tank is the best way to create a compacted tank; any liquid will eventually evaporate after a few weeks and all that will be left is a nice, even layer of dried out waste that will block your discharge line, making it impossible to dump later.

  12. When possible, store your RV with a black tank full of water, treated with a high-quality bacteria or enzyme treatment.

    Be sure to dump your tank of all the human waste and rinse well before refilling it with water and adding a bacterial treatment like Unique RV Digest-It. This will help deep clean your black water holding tank while the RV is being stored, but drain the tank if you suspect temperatures may drop enough to freeze.

We invite you to view the videos about The Unique Method for the different types of RVing


Full Hook-Up Campers

Full Time Campers

Dry Campers

In the next article, we’ll walk you through the steps for properly caring for your gray/galley tanks.

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