I went back and forth about adding a comment to your other thread about your newly found excitement about an eco pool. I didn't want to rain on your parade, and I didn't want to fire up a debate about it in a forum that is not into supporting such a thing (for good reason). But if you're looking for another 2¢, I'll give it a go.
Like ozone and uv systems, and pretty much every other non-chlorine solution, including eco, (except maybe bromine?) the claims about their ability to provide healthy swimming water with little or no chlorine are absolutely true, if you run and maintain them perfectly, and you can manage to keep all unwanted things out of the water, like, oh, say, humans!!
These systems can, and I'm sure do, provide safe water, but only for an unknown amount of time. Could be weeks, days, hours or minutes! That's what you're risking. All it takes is a person with, uh, lets just say less than ideal hygiene, or one with some sort of infection, or a bird flying overhead, or a raccoon pooping on your step, or any of hundreds of other ways your pool water can be exposed to harmful agents, and your beautiful, healthy water will be compromised for hours or days while these non-chlorine systems work to rid the water of potentially dangerous pathogens.
Without the residual protection that chlorine provides, working to kill such nasties within minutes, 24/7, you're risking the health of anyone that gets in your pool. It's not a good idea, at all, in terms of a swimming pool. If you just want to look at it, and enjoy it, and put some lily pads in it and frogs and fish, then eco away! Not fit for people, though, IMO...