With the drought continuing in SE Texas I may soon have to replace more water due to rising CH levels. I've done this before the mandatory water rationing rules were put into place, but if you follow the restrictions a full or even a 50% replacement is impossible or impractical (we can only use significant amounts of water (for lawns, topping up pools, etc.) between 9pm-3am MWF). So having water trucked in or doing RO may be the only option unless we get some rain. Any idea how much that would cost in SE Texas? Yes, I know I could do a bunch of small partial drains/refills.

It might not even be available in your area. You could try calling local pool companies to see if they provide the service or know anyone who does. Here is a company in Austin, but they might be too far away. If they don't service your area, they might be able to recommend someone.

An alternative to RO is to use water softener resins. More time, but can be a DIY.

Thanks. I found them as well and just emailed them.

Interesting. Are there any instructions on that published? How is it done?

It was a DIY project on my pool. I will get the details together and make a post this weekend.

I'm interested as well. The Austin company that does RO just told me they not aware of anyone who does RO in Houston. Not too surprised--until this drought (which is unprecedented in my 45 years of living in the greater Houston area) came along there probably was zero demand in Houston for RO for pool water.