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

[chem geek]

Adding the "Yellow Stuff" has helped remove the yellowish stains, albeit very slowly. Will add as directed every 60 days. This it seems is a long slow process.

Jack's Magic "Yellow Stuff" is 98% Sodium Bromide (see this link or look on the bottle for verification). Adding bromide to chlorine pool is a bad thing since once your pool is a bromide pool, it stays a bromide pool (unless you shock with chlorine repeatedly in sunlight). What you have been doing by adding "Yellow Stuff" is replacing chlorine in your pool with bromine just as you did earlier with "Yellow Treat".

Chlorine converts bromide to bromine, but uses up chlorine in the process:

HOCl + Br- --> HOBr + Cl-

Unfortunately, bromine is not as good an oxidizer nor disinfectant as chlorine which is part of the reason the above reaction occurs in the first place. When the bromine then disinfects or possibly oxidizes something, it does the following:

3HOBr + 2NH3 --> N2(g) + 3H+ + 3Br- + 3H2O

but then the bromide uses up chlorine as shown before.

The only plus side to having the bromine is that it will not break down in sunlight the way that chlorine would (even with CYA it breaks down, but more slowly) and it doesn't outgas as quickly which is why it is often used in hot tubs. It theoretically kills yellow/mustard algae, hence "yellow" in the product name, but chlorine shocking and borates kill algae too.

Read this post from Ben for more info (the same link Evan provided earlier). Apparently, repeated shocking of your pool with chlorine in the sunlight may remove your bromine. The "Yellow Stuff" is an algicide, NOT a stain remover, but your Borates and PolyQuat would do a much better job at preventing and killing algae. Either the stains are fading on their own or the oxidizing of bromine and chlorine are fading them (in which case simple shocking of chlorine should do the trick over time) or the Borates are fading them (killing algae). If you put a Trichlor tablet on the stain and it fades, then it was likely algae; otherwise if it's a metal stain, then you need to use one of Jack's Magic other products for stain removal, but not The Yellow Stuff.

If some algae stain doesn't come off with chlorine shock plus possibly brushing, you can try using PolyQuat. At least with PolyQuat algicide, it won't interfere quite as much with the chlorine though we have found that it does consume some of the chlorine but apprently converts to a byproduct that still inhibits or kills algae (see this post for more info).

If I were you, I would just stick with the Borates and forget adding other chemicals to your pool such as the "Yellow" stuff. If the stains continue to fade, then you just need patience. If they don't, then try PolyQuat first and then the Jack's Magic stain removal products (but NOT "The Yellow Stuff").

Richard