
RV liquid RV and holding tank treatment
Rid-X Holding Tank Deodorizer, Liquid
4 to 10 oz per tank, by tank size
Best for RV, boat and portable toilet tanks, dosed by the capful
up to 8 treatments
$3.50 per treatment
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How to dose Rid-X Holding Tank Deodorizer, Liquid
Step 1
Know your tank
Find the size of the holding tank in gallons, from 20 to 50.
Step 2
Measure by size
4 oz for 20 gallons up to 10 oz for 50, with fresh water.
Step 3
Add it to the tank
Pour it into the holding tank through the toilet with the fresh water.
What it does
Match the dose to the size of your holding tank
This bottle is written for holding tanks: the one under your RV, the one on your boat, or a portable toilet. You measure the dose by the size of the tank and add fresh water with it. A 40 gallon tank takes 8 oz of liquid and one gallon of water, and a 20 gallon tank takes 4 oz and half a gallon.
The 48 fl oz bottle gives up to 8 treatments, and the 24 fl oz bottle is half that size. Your tank size sets how fast a bottle goes, since a 50 gallon tank draws 10 oz each time. According to the maker, the liquid carries bacteria and enzymes that break down waste and tissue and fight odor. Those are the maker's words. The bottle comes in Fresh Scent.
- For RV, boat and portable toilet holding tanks
- Dose by tank size, from 4 oz up to 10 oz
- Paired with fresh water, the amount set by tank size
- 48 fl oz bottle: up to 8 treatments
- Also sold as a 24 fl oz bottle
- Fresh Scent, with bacteria and enzymes according to Rid-X
Compare the Holding Tank Deodorizer, Liquid with the 1 other product on the rv and holding tank treatment shelf, all part of the Rid-X septic and RV range.
Directions and best results
- Look up your holding tank size in gallons in the RV or boat manual.
- Measure the liquid for that size: 10 oz for 50 gallons, 8 for 40, 6 for 30, 4 for 20.
- Measure the fresh water as well, from 1.25 gallons for 50 down to half a gallon for 20.
- Add the liquid and the water to the holding tank together.
For best results
- Dose for the tank you actually have, since the smaller line on the chart gives a big tank too little.
- Cap the bottle after each dose, keep it away from children and pets, and never mix it with other tank chemicals.
- For a septic tank at home, choose one of the monthly Rid-X septic treatments instead.
Label facts
| Brand | Rid-X |
|---|---|
| Type | Holding tank liquid |
| How you dose | 4 to 10 oz per tank, by tank size |
| Supplies | 24 fl oz (up to 4 treatments), 48 fl oz (up to 8 treatments) |
| Form | Liquid |
| For | RV, marine and portable toilet holding tanks |
| 50 gal tank | 10 oz liquid, 1.25 gal fresh water |
| 40 gal tank | 8 oz liquid, 1.00 gal fresh water |
| 30 gal tank | 6 oz liquid, 0.75 gal fresh water |
| 20 gal tank | 4 oz liquid, 0.50 gal fresh water |
| Bottle | 24 fl oz or 48 fl oz |
| Treatments | Up to 8 per 48 fl oz bottle |
| Scent | Fresh Scent |
| Contains (maker's words) | Bacteria and enzymes |
Safety and sources
Empty a treated holding tank only at an RV dump station, a sewer hookup or through a pumper. The EPA alert for RV owners warns that some holding tank deodorizers contain formaldehyde, which can kill the bacteria of a septic tank, so ask before you dump a treated tank into a home system.
Questions
About Rid-X Holding Tank Deodorizer, Liquid
How much Rid-X holding tank liquid do you add to a 30 gallon tank?
Use 6 oz of liquid with 0.75 gallon of fresh water. The chart scales from there: 4 oz with half a gallon for 20 gallons, 8 oz with a gallon for 40, and 10 oz with 1.25 gallons for 50. Measure for the tank you have, not the next size down.
How many treatments are in a bottle of Rid-X Holding Tank Deodorizer?
Up to 8, the 48 fl oz bottle says, and that count fits a 30 gallon tank at 6 oz a time. A 20 gallon tank at 4 oz gets more out of the bottle, while a 50 gallon tank at 10 oz gets four full doses. The 24 fl oz bottle holds half as much.
Can you use Rid-X Holding Tank Deodorizer in your home septic tank?
It is not written for one. The label gives doses for RV, marine and portable toilet holding tanks of 20 to 50 gallons, and the product is absent from Washington State's December 2024 list of septic additives, where the Rid-X septic products appear. For a house tank, use one of the monthly septic forms.


