Creativity Pool Forums

Yes, I am THE crazy cat lady. I have somehow accumulated 10 cats. I find abandoned or feral cats who need me, or my kids just bring home pregnant strays, and I don't have the heart to throw them out or take them to the pound to be killed. So I get them checked by a vet, fixed, and now they live with us as INDOOR only cats, it's not safe outside for poor little housecats anymore. So my idea is, I have put a huge fully enclosed dog kennel next to my house and installed a cat door so they can get some safe "outdoor" time. It's has different levels on the sides so they can climb and a covered area so they can get out of the sun or rain. I want to put something like a children's pool over there and fill it with litter. I recently bought a CATSAFE or something like that litterbox at Petsmart that was a round bowl that slowly rotated through some grates and kept the box clean. I gave mine away on Craigslist because my cats wore the thing out in 9 days and it stopped working. I'm thinking if I can make a giant industrial strength one with a children's pool, that would be awesome. I don't want money for the plan since I got the idea off a smaller low quality version, but I do want to figure out how to make one myself or buy one if someone else knows how to make them. I would of course want something stronger than a cheap children's pool too, but the same size, maybe something from a feed and farm store. Any engineers out there got any ideas?