Thetford Additives: What You Need To Know


The Thetford Porta Potti has been around for more than 70 years and is sold worldwide. Millions have been sold all over the world. But the range expanded to include permanent and cassette toilets. Most RVs nowadays have a Thetford built-in cassette toilet, which are easy to use and an absolute blessing during cold and rainy nights at the campsite, especially when you are travelling with kids.

A large variety of Thetford additives is available, in different colour and different smells, to help you care for your toilet. What colour is used where? What is the difference between the Aqua Kem Sachets and the concentrated additives? And is special toilet paper really necessary?

thetfordThetford Toilet Care Products come in four different categories: waste-holding tank products; flush water tank products; grey water tank products; and maintenance products. Let’s have a close look at each of them…


Let’s start with the waste-holding tank products, which do most of the hard work. The are designed only for use in portable and cassette toilets. Unlike many household products, they are safe to use in combination with seals and plastic parts. For example, waste-holding tank products liquefy the toilet waste, eliminate nasty smells and reduce gas build-up in the toilet tank, resulting in a fresher-smelling bathroom and an easier to empty waste tank.

thetfordThe waste-holding tank products come in two colours: Aqua Kem Blue and Aqua Kem Green. The purpose of both colours is the same, but the key difference is that Aqua Kem Green can be safely emptied into a septic tank a designated dump point; Aqua Kem Blue must be emptied in a designated dump point. Aqua Kem Blue comes with a very dark blue dye, which makes it more pleasant to empty the tank as the liquid that comes out is still blue (instead of brown or yellow). Both the Aqua Kem Blue and the Aqua Kem Green come in a water-soluble sachet and a concentrated liquid. 

Benefits of Concentrated liquid

  • Available in pine, citrus, lavender and eucalyptus fragrances;
  • Four different fragrances available;
  • When using a smaller Porta Potti, you can easily halve the dose; and
  • Less packaging required

Benefits of the sachets

  • Pre-dosed, so the ideal amount of product is always dispensed;
  • Lightweight and easy to store; and
  • Water soluble sachet; no spilling of liquid





Aqua Rinse Concentrated keeps the flush water fresh by preventing limescale build-up in your flush water tank and ensures a smooth and pleasant-smelling flush.

Nowadays, most Australian RVs nowadays use the central water tank to flush the toilet, which means you are not able to use the Original Aqua Rinse Concentrated. Using the Aqua Rinse Concentrated in your fresh water results in a pink shower and potatoes that taste like lavender, as both the bathroom and the kitchen use this same tank.

thetfordTo avoid mixing additives in the same tank, Thetford introduced the Aqua Rinse Spray a few years back and you can spray it directly into the toilet bowl. It coats the bowl with a thin layer to ensure a smoother flush and lubricates the toilet seal. Aqua Rinse Spray has a pleasant lavender smell. After flushing the toilet, allow some time for the lubricating ingredients to work into the bowl and seal.


There are two grey water tank products available: Grey Water Fresh Concentrated (for daily use) and Duo Tank Cleaner Concentrated (for periodical use). The Grey Water Fresh Concentrated replaced the former Tank Freshener and is used directly into the sinks, drains and shower, reducing deposit formation in the pipes and grey water tank, as well as keeping the tank fresh for longer.

thetfordThetford’s latest addition to the additives range is the Duo Tank Cleaner Concentrated. The word ‘Duo’ refers to its ability to clean the grey water tank and the waste-holding (toilet) tank. The Duo Tank Cleaner replaced the Cassette Tank Cleaner, which used to be the purple bottle, and which was only suitable for cleaning the waste-holding tank. The Duo Tank Cleaner removes scale and grease deposits, all without scrubbing!


There are several maintenance products and special cleaners available to keep your toilet running smoothly. 

Red = Bathroom Cleaner: A cleaning agent for safe, easy, and thorough cleaning of all plastic surfaces in the caravan or motorhome. You can also use this cleaner for all other plastic surfaces in and outside your RV, including the cupboards and shower.

Yellow = Toilet Bowl Cleaner: Unlike your domestic toilet cleaner, this is safe to use on plastics and seals. Most household toilet cleaners contain bleach, which damages mobile toilet plastic parts and seals. The Toilet Bowl Cleaner is just as powerful and ensures your portable or cassette toilet remains fresh and clean. Although the liquid colour is yellow, don’t worry, it doesn’t stain your toilet bowl; in fact, it adds a layer of protection and smells great!

Orange = Seal Lubricant: Recently released in Australia, the Seal Lubricant was specially developed for mobile toilets and is safe to use on all seals and plastic parts. No more messing around with olive oil or other non-petrochemical products.

thetfordThe lip seal in your toilet tank is probably the most crucial part of your toilet, as this seal prevents the tank from leaking and keeps any smells inside the tank. Lubricating your lip seal with the right product will maintain flexibility and increase longevity. Best to spray the seal a few times a year, especially before and after storage.

Do you suspect your toilet tank is leaking despite keeping the seal lubricated? Best to fill the tank with fresh water and hold it upside down to find the leak. All seals in the waste-holding tank are available as spare parts and easy to replace yourself.


Aqua Soft toilet paper is a two-ply, quickly dissolving toilet paper that breaks down inside the waste tank. Household toilet paper does not dissolve quickly; it clumps together and will likely clog your toilet, making it harder to empty the cassette. 

Another reason to use special toilet paper is because normal household toilet paper can stick to the moving parts inside the tank, causing it to malfunction or leak. And yes: number twos are allowed in Thetford mobile toilets!

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