pH vs. alkalinity

[fishkat]

My pH is good at 7.4 but my alkalinity is reading high at 300-350. Is there any way to bring the alkalinity down without bringing down the pH? Everything I've read states to use pH decreaser to bring down alkalinity, but I don't need to decrease my pH. I've been a spa tub owner for 5 years now and have not experienced this issue prior to now. Any insight would be greatly appeciated.
fishkat

[Jacuzzi Jim]

How old is the water?  High alk is not the end of the world, you can decrease it but many times I just leave it alone on my own spa and it's fine till I am ready to drain it.   If you water is more than 5/6 months old it may be ready for a change??

[chem geek]

If your pH doesn't tend to rise, then don't worry about it unless your Calcium Hardness (CH) is higher (say, 100 ppm or more).  You may be using a net acidic sanitizier (Dichlor granular/powder or bromine tabs) or oxidizer (MPS) that's helping to balance the pH.

If you do want to lower the TA, then that is done through a combination of acid addition WITH AERATION of the water, which is pretty easy to do in a spa with jets.  The procedure is detailed in this post.