Borax Floater in Closing Kit

[chem geek]

I have resolved not to buy a kit to close this year.

With all these posts about Borates and Borax, I am wondering why the pool thieves include it in their kit. What would the function be to add a pound or 2 slowly from a floating half gallon jug with an ice pick hole or two in it.

I'm guessing it is more for pH than algaecide since the kits come with Quat.

I believe you are correct since the algaecidal properties of the Borates don't work until the amount is high enough, at least 30 ppm. In fact, some algae actually like a small amount of borates so the low concentrations certainly aren't helpful (that brings up controversial issues with using Borax for pH control, but I don't think it's a problem so long as chlorine levels are maintained). So yes, I suspect that the Borax is just used for pH control in these kits assuming that something else they have is acidic, probably Tri-Chlor.

Richard