Pool ionizers alone won't cut it in hot climates.

Not really. Ionizers help reduce the amount of chlorine you need, but in a hot climate where algae thrives, they are not a replacement for an oxidizer like chlorine or shock. Think of them as a helper, not a solution.

Copper and silver ions kill algae and bacteria slowly. Hot sun speeds up algae growth, and ionizers can’t keep up on their own. You’ll still get green water unless you maintain a small chlorine residual (1–2 ppm) or use a non-chlorine shock regularly. I’ve seen people try to go chlorine-free with ionizers in Arizona and Texas – it works for a month, then they’re scrubbing the walls.

If you want to cut chemical use, an ionizer is fine. But plan on keeping a low level of sanitizer in the water, especially during the hottest months. The ionizer just makes that job easier, not obsolete.

Skip the ionizer if you’re hoping for a set-and-forget algae solution. You’ll just end up buying algaecide anyway.