Do borate products (Supreme, Optimzier, etc.)work as claimed?

[chem geek]

I posted some info on the other tetraborate thread, but I did find this WHO document full of some useful information. It would appear that, at least in simulated seawater, 100 ppm is more effective in inhibiting or killing algae than 50 ppm, but pool water is not sea water. There seems to be no question that Boric Acid (or its borate ion) inhibit growth of several kinds of microorganisms, but I just find it suprising to see the relatively large drop in chlorine usage that Evan (waterbear) has noticed so far. Most chlorine loss is during the day due to breakdown from sunlight (UV) so to truly cut down chlorine consumption significantly a substance has to prevent this loss. My concern would be that the mechanism for this (if it exists) could be similar to CYA and that could mean a reduction in chlorine effectiveness.

Also, with regard to adding a bunch of HCl to the pool, remember that the combination of adding Borax and Muriatic Acid gives you the boric acid you want plus salt (NaCl). That is, the end result is nothing nearly as toxic as the original HCl you started with. It's kind of like adding Muriatic Acid (HCl) with Lye (NaOH) to produce salt and water. You can't think of the result of mixing toxic chemicals as producing a toxic result. I agree that Muriatic Acid is a bit of a pain to handle, but using gloves and holding one's breath or looking away should be sufficient precaution (wearing glasses would be an extra safety factor in case of splashing of drops).

Richard