We've had lots of good reports from owners with Borate levels of 50ppm.
BTW, Sodium Tetraborate is sold for about $.80/lb in your grocery store. It's called 20 Mule Team Borax and most of us use it as our first choice to raise pH, ahead of Soda Ash.
Pool dealers DO sell a Borate additive that adds borates at a higher level, but it's no better for your pool, just better for their bottom line.
Borax is the easiest and cheapest way to do it.

Even if you don't go the Borate route (I don't but have no objection to it), you SHOULD use Borax as your first-line pH increaser. It doesn't raise Total Alkalinity as much as Soda Ash does.

BTW, Soda Ash is ALSO available at your grocery store, as Arm&Hammer Washing Soda (in the yellow box). It's EXACTLY the same chemical, Sodium Carbonate, as the expensive pool brand pH raising chemicals.

Carl