I am in the “I could take em or leave em camp” for the most part.
I have went without replenishing it in my pool & noticed no difference in ph rise. I concluded that with my fill ta only being 110 & the fact that I don’t top off a ton that adjusting my pool’s ta to 60 is doing the brunt of the work in my vinyl lined pool. I have a swg so the feel i have likely comes more from the salt
. I haven’t noticed any difference in “sparkle” with or without borates.
In my spa I generally add 50ppm borates upon each refill after lowering ta to 50-60 - it’s helpful effects are more obvious there due to the constant aeration although lowering the ta is still responsible for most of the help. When going without borates the ph doesn’t stay quite as stable in the spa for me so I use them when possible.
Borates are definitely not a magic solution but can be a helpful additional step to take for those who have multiple other conditions working against them such as high ta & ph fill water, a plaster surface, water features, & who struggle with frequent ph rise along with keeping their csi in check to protect their surfaces & swg after they have done all they can do to get those things in line otherwise.
It’s truly a case by case thing in my opinion as to who may benefit enough to worry with adding them since their presence adds more complexness to something we are ultimately trying to keep simple