How do I keep my pool water clean without nasty chemicals?
Still chlorinated, but if handling chemicals is the issue, how about a salt water pool?

The alternative I've seen pushed is copper-oxygen system.  I can't say how effective it is, but last I checked it is not approved by the EPA for sanitizing water.  I've also read that they take more attention and care.

Just based on experience having a pool in full sunlight - UV isn't going to do the job by itself.  I think the filters they sell are designed to reduce your chemical dependency, but not eliminate it.  Same with ozone generators.