We purchased the HTH kit and it helped a lot thanks. We were able to finally get an accurate pH reading. Unfortunately the CYA test did not shed any light because it never turned cloudy, which is integral to performing the test. My guess is that the level is over 100, the highest value on the cylinder, and that's why it didn't work at all.
I saw an empty bottle of cell saver (for the SWG) in my mom's pool stuff and asked her about it. She forgot that she had added it. I looked to see if that's where the CYA could have come from, but it didn't show any ingredients on the bottle. I did see that it calls for using 16 oz in a 10,000 gallon pool, but my mom used all 32 oz. in a 4,400 gallon pool, so whatever is in it got added to the pool at 4x the correct amount.
The pH came down to 7.2 so we are aerating now, but the alkalinity is still showing high, over 400 ppm. Added more acid overnight but the levels are still the same.
The algae is getting bad, so we are going to move on to shocking it before it gets worse. I never knew fixing a pool would be so complicated, but this definitely drives the point home that an accurate test kit is going to save a lot of time and money. At least I am glad we got the pH to lower and knew which products to use to not make certain situations worse. Should be interesting to see how much chlorinating liquid it takes to bring it to a shock level, not knowing for sure what the CYA level is.