TA and PH swings

Mar 17, 2017
Spring, TX
So I have a fairly new pool and the PH is high (8.0 or so) everyday when I test it. So add enough MA to bring it down to 7.4 or so and then next day back up to 8.0. Pool builder said I'll be chasing this for a good 6 months but didn't say why. My TA was 80-120 up until about two weeks ago when I tested and it was 60. So I added baking soda. That brought it up to 80...but then the PH went high so I added MA and then that brought both down. How do I get out of this yo-yo effect with PH and TA as I try to raise one but lower the other?! All my other readings are all within normal range per TFP standards and I have zero water issues as the water is crystal clear. Thanks for any info!