My bet is on air bubbles causing the foam. If it were my pool, I would turn the SWG off for now, and see if that eliminates the bubbles altogether. It would also give you a chance to fix the leak.

Don't give up on the pool yet--you'd be amazed what a lot of bleach and some patience will do for a pool!!! Keep your chlorine at 15, testing and adding more as needed as many times a day as possible--the more consistently your chlorine is up, the faster it will clear.

There are test kits that will measure FC up to 50 ppm--the Taylor K2006 is a good one that will measure all you would need. Leslie's also carries a similar kit. What you want is a drop-based kit that will measure free chlorine, combined chlorine, CYA, pH, ta, and CYA. The ones that do all that accurately are a little pricey, but they will save you hundreds of dollars in the long run and are well worth it. In the meantime, you can use CarlD's "shotglass method" to estimate your higher chlorine levels....get your regular pool sample and dilute it 1:2 with non-chlorinated (distilled or tap that's been dechlorinated) water. Mix the sample, test as usual, then multiply your result x 2. This will give you a ballpark chlorine level for now. If you need to go higher, then mix it 1:3 and multiply the result x 3. You lose a little accuracy everytime you dilute, but again, it'll give you a good ballpark idea of what your chlorine is.

Your pH may or may not be as high as your testing shows--normally when your chlorine is above 10, your pH is going to test falsely high. However, you already know that aeration raises pH, and if I'm correct in thinking that your foaming is caused by air bubbles, then that is certainly a cause for your pH rise quickly. You'll know if that's the culprit by turning off the SWG and seeing if the pH stabilizes, even with your chlorine levels that high.

Hang in there--I know patience is hard to come by when you're looking at a pool that won't clear, but don't give up on it yet!!

Janet