I have 2 cats, and recently repurchased a scoopfree litter box. I had one last year and it was great however it broke. The previous litter box was downstairs and I never smelt it until about 3 weeks after changing the tray however since getting a dog the new one has to be upstairs where she can’t get to it. The litter box smells after 3 days! I’m mixing the crystals twice daily and spraying down the plastic cover as somtimes my cats won’t fully step in. Is there an alternative litter I can try as I feel I may aswell have just stuck with a regular litter box as this one was meant to be no maintenance?