There are 3 cats using 2 litter robots. Maliik has his own since he is in semi-permanent isolation. I add fresh litter about 1x week. The globe holds 10 lbs of litter and I like to keep it filled to the fill line. A couple of the cats pee like horses and if the litter gets too low, the clumps stick to the liner and don't empty during the clean cycle.
I change out the litter every 1.5 to 2 months and do a thorough wipe down of the inside with a vinegar solution. I totally change out the litter on that cycle whether it looks like it needs it or not -- a habit left over from the plastic bin days and because I think it's just good hygiene. I also do a light wipe down when the litter dust totally coats the inside of the globe or when one of the cats manages to pee against the back of the globe or whenever it looks like the inside of the globe needs it.
I've watched videos of folks who take it completely apart and hose out the globe and wipe down the rest. I don't think that's necessary if you keep the litter topped off. Twice a year, I'll take it apart and clean everything.
