Review on Premium PetSafe ScoopFree Cat Litter Crystal Tray Refills - 3-Pack for Self-Cleaning Boxes - Non-Clumping, Odor Control - Choose Original Blue, Lavender, or Sensitive! by Carmen Rosario

We have 2 cats in a small apartment. I would say 5 stars for the toilet. 5 stars for blue litter. 2 stars for clear. The trash can works great. The litter box always seems clean and tidy to me. My cats had no problems with it from the start. However, in using it, I learned that the only way to make this box inexpensive is to use scented/colored crystals. Basically, that's because the system cleans the litter box well, but because the litter doesn't stick, it doesn't clean the cat's urine. So unless you buy scented/colored crystals you will smell the litter. very fast. Basically, I started with the blue crystals that came with the litter box. Everything worked great. The trap was full before the crystals even started smelling. I simply used a dust pan to clean and used the crystals for the entire recommended window for 2 cats. I figured 1 pack of 3 per month would be more than enough. However, I prefer colorless products. When I signed up for a monthly refill subscription, I opted for a 3-pack in a clear color. Bad decision. The apartment smelled of cat pee in less than a week, and all the crystals were already yellow-brown. I only had to use Febreze in the closet to stretch the 3 pack over a month until my next subscription shipment (which I replaced with blue crystals again). If I continued to use clear napkins would I have to change at least 4 trays a month which would cost about $60 a month to refill? No way. In summary, this system is great, especially when compared to much more expensive automatic toilets, but in a multi-cat household you'll probably need scent crystals to make it worthwhile.