How much is the TDS increased if Borax is added to 50 ppm

[chem geek]

Bromide (and bromates) and Borates are two completely different things. You have Borate, Boric Acid, Borax or Boron (take your pick as all terms could be used) in your pool, not Bromide or Bromates. I know this is confusing -- just focus on the first three letters -- Bor... is the stuff that helps prevent and kill algae and helps stabilize pH (and makes the pool sparkle) while Bro... is the alternative sanitizer to chlorine, often used in hot tubs, and should not be used in a pool unless you permanently want your pool to use Bro... (i.e. you have to drain your pool to remove Bro...).

The high level of Borates in your pool will help prevent algae and kill some of it as well. That means that the chlorine won't have to so chlorine usage will be less because of it, at least in terms of killing new algae. However, the chlorine will still try to oxidize the algae that is there even if much of it is dead and could get somewhat consumed because of that. If you find that it isn't dropping, then the algae is dead and the easy-to-oxidize stuff has been taken care of so all that is left is to filter out the dead solid cells and you are done. It sounds like your water finally turned clear so that's that!

As for recommending anything different than chlorine, I would say that isn't true. Though the Borates (Borax) may have helped speed up the killing of the algae, the decision to use Borates is a yes/no decision for whether you want your pool to always have borates or not. You cannot get rid of the borates in your pool except by dilution (not that you'd want to get rid of Borates as they generally do no harm, but I suppose if you built up more than 100 ppm you might want to dilute to cut back). So using Borates isn't something to tell people to do when they have an algae problem -- it's a separate decision and yes, if they already decided to use Borates then it appears that they will have less problems with algae.

And yes, using Borates reduces chlorine consumption (as waterbear found to be true), but that won't put Wal-Mart out of business. You'll just need to buy less chlorine...I'm sure Sam's folks will find other things to sell to you.

Richard