The pH definitely needs to come down, the problem is most test kits can not discern pH above 8.0, so yours could actually be far higher than 8 and you wouldn't know. 8+ pH can cause scaling, which is unsightly and can cause problems especially in your heater. I'm not so sure it would cause eye irritation, though. This is something you should read: http://www.poolsolutions.com/tips/er...uidelines.html . Near the bottom of that document is specifically talks about high pH and eye irritation. My guess is that you have something else going on, perhaps some combined chlorine from fighting algae?

Here's an excerpt from the article:
The grandfather of swimming pool eye irritation studies, a study of Yale University swimmers by Dr. Eric Mood, published in 1951 actually shows that eye irritation is lower at pH 8 than at pH 7. Later studies show that chlorine, chloramines, salinity all play a role in determining eye irritation.
What are all the readings you got with your walmart kit? Combined chlorine can definitely irritate eyes (does your pool "smell" like chlorine?), but we can only guess without a full set of test results.


As for borax, if he's allergic I would not do it. From what I've read I don't think you can remove borates without draining. The recommended washing machine dose for borax is 1/2 cup (3.6oz) to ~40gal which I believe is about 75ppm.... IF I calculated it right.