Hi Paul, the chlorine test ignores cya so it causes some confusion. What we know is free available chlorine is mostly bound to the cya so not available to disinfect ( this point has been the subject of some disagreement over the years) but overlooking that hence why we need the higher chlorine level compared to what some books and internet pages say. Pool vinyl liner or glass fibre? If so, and your pH is pretty stable don’t add alk+ this would just mean having to counter pH rises later as the carbonates off gas from the pool. Good news is pH is not an issue provided it’s more than 6.9 as that can cause eye irritation. You can run your pool anywhere up to about pH8.5 without issue when you have CYA in the water. Different rules apply when the pool is not using CYA. This is because the compound of chlorine and CYA is the dominant source in the pool and not pH dependent. I posted some info on this a while back, might be worth you taking a look.