Quote Originally Posted by no1ford
Ok-well I still have some ph minus from opening-so I will try that first. I added 1/2 cup to start for an 18x48 pool. I have read that if the ph gets to low it can harm the liner-so I a liitle hesitant. I will re-check in two hours. On average how long does it take for Alk to lower-is this another long process? Should I keep my filter running?

A couple more questions:

And I am still unclear about aeration.
by lowering the pH you have shifted the TA buffer system of carbonic acid/carbonates/bicarbonates to more carbonic acid and less of the other two. Club soda is carbonic acid! (carbon dioxide gas dissolved in water) If you shake the bottle of club soda (aerate it) it goes flat (you have driven off the dissolved carbon dioxide). You want to do the same with your pool (I know you can't shake it but you want to disturb the water as much as you can, perhaps a pipe in the return with a 90 deg elbow to create a fountain effect, or 10 kids having a splashing contest)
One alk is adjusted do I add borax to raise ph back.
No, as the carbon dioxide is driven off the pH will rise on its own as the TA goes down. Just stop aerating when the pH is where you want it.
Can I continue to add my bleach as normal during this process?
Yes
I really appreciate your help. By next season I should be a pro!!
Hope this helps.