Scooper Luxury Pro XCATLINK
- Clumping clay
- Supported
- Tofu
- Excluded
- Crystal / silica
- not published
- Wood pellet
- Excluded
- Recycled paper
- Excluded
Litter compatibility register
Using the wrong litter can jam the mechanism and void the warranty, and the exclusions are buried in manuals rather than printed on product pages. This is every published rule we could find, in one grid.
Compatibility rules checked
| Model | Clumping clay | Tofu | Crystal / silica | Wood pellet | Recycled paper |
|---|---|---|---|---|---|
| Scooper Luxury Pro XCATLINK | Supported | Excluded | not published | Excluded | Excluded |
| 4Litter-Robot | Supported | not published | not published | not published | not published |
| Purobot UltraPETKIT | Supported | Supported | not published | not published | not published |
| Crystal (disposable tray)PetSafe ScoopFree | Excluded | Excluded | Supported | Excluded | Excluded |
4Litter-Robot
- Clumping clay
- Supported
- Tofu
- not published
- Crystal / silica
- not published
- Wood pellet
- not published
- Recycled paper
- not published
Purobot UltraPETKIT
- Clumping clay
- Supported
- Tofu
- Supported
- Crystal / silica
- not published
- Wood pellet
- not published
- Recycled paper
- not published
Crystal (disposable tray)PetSafe ScoopFree
- Clumping clay
- Excluded
- Tofu
- Excluded
- Crystal / silica
- Supported
- Wood pellet
- Excluded
- Recycled paper
- Excluded
PETKIT excludes by size, not by type, and it is the better rule. The Purobot Ultra excludes anything longer than 12mm or wider than 3mm, whatever it is made of. That is the only size-based rule we found, and it is more useful than a brand list, because it tells you what to measure rather than what to trust.
The exclusions in full
CATLINK Scooper Luxury Pro X excludes tofu, recycled paper, wood pellet, non-clumping clay.
PetSafe ScoopFree Crystal (disposable tray) excludes clumping clay, tofu, wood pellet, recycled paper.
The pattern is consistent once you see it: every drum-style automatic is built around a clump. Anything that absorbs rather than clumps, breaks apart rather than holding together, or comes in a pellet too big to sift, is excluded somewhere. Crystal is the reverse case: the PetSafe ScoopFree requires it and works with nothing else.
What compatibility costs you
Litter type is a running-cost decision as much as a compatibility one. Clumping clay runs about a third the price per kilogram of tofu, so a box that accepts only tofu, or an owner who prefers it, is signing up for a materially higher annual bill. The running-cost register has the current per-kilogram prices.
Common questions
Can I use tofu litter in an automatic litter box?
It depends entirely on the model, and getting it wrong is one of the few mistakes here that can void a warranty. PETKIT supports tofu explicitly. CATLINK excludes pure tofu and long-strip tofu outright, and supports only bentonite or a bentonite and tofu mix under 13mm. Whisker recommends clay clumping litter for the Litter-Robot 4. Check the exclusion before you buy a bag, not after.
Do wood pellets work in a self-cleaning litter box?
Not in the drum-style automatics. Wood pellets break down into sawdust rather than forming a clump, so a sifting or raking mechanism has nothing to lift out and the residue works its way into the machine. CATLINK excludes wood-based pellets by name. Wood pellet litter is excellent, but it belongs in a sifting tray built for it, such as the Oz-Pet system.
What is the safest litter to use if I am unsure?
Clumping bentonite clay, in a fine grain. It is the one type every drum-style automatic in this table supports, it is the cheapest per kilogram, and it forms the firm clump the mechanism is designed around. The trade-offs are dust and weight, and it is not the most environmentally comfortable choice, but on compatibility alone it is the safe default.
Can using the wrong litter void the warranty?
Yes. Manufacturers exclude litters because they jam or degrade the mechanism, and damage traced to an excluded litter is generally not covered. This is the single cheapest mistake to avoid on this site: a bag of the wrong litter costs twenty dollars and can cost you a machine worth over a thousand.