Converting to BBB

[chem geek]

Thanks- I'll check my levels and post them today, but just curious about the Borax/M. Acid method to adjust PH vs pool store bought PH-UP and PH down. Is it simply an economical issue or are the other benifits to using the borax/M. acid? I'm asking for two reasons 1) I have quite a bit of the pool store product left over and 2) I like the idea of having the specific amounts to add with the pool store PH adjustment products .

Yes, it's mostly an economics issue and the pH Up and Down products may be OK for you to use, depending on what they are, at least until you use them up. Read the labels and see if you can figure out if they are what I say below.

The pH Up is likely to be Sodium Carbonate which will not only increase your pH, but will also increase your Total Alkalinity (TA) (by more than what the pH would do alone). This is because you are adding "carbonate" to your pool -- making your pool more carbonated, just like a beverage! It is possible, though unlikely, that the pH Up is Sodium Hydroxide in which case this will be quite similar to Borax and will not increase TA (beyond that caused by the increase in pH).

The pH Down is likely to be Sodium Bisulfate which will add sulfates to your water. A little of this isn't terrible, there may even be some sulfates in your make-up water, but you don't want to overdo it. It has been reported elsewhere in this forum that Sodium Bisulfate can damage plaster surfaces, probably because it doesn't dissolve immediately so perhaps it would be better to put it into a large plastic bucket of water first (assuming the plastic is rated for acid) and then add it to the pool that way. In any event, you should add most chemicals to your pool over a return jet at the deep end to ensure the best mixing and dilution. The better way to lower pH is to use Muriatic Acid which is a liquid usually sold by pool stores as well (and some non-pool stores, etc.)

As for the amounts to add, the instructions on the bottles you have are approximate and only apply to pools with "typical" conditions of TA 100 and pH 7.5 as starting points. I can give you the same rule of thumb for Borax which is that 1 pound of 10 Mule Team Borax (which is Sodium Tetraborate Decahydrate) will raise the pH by 0.21 in a pool of 10,000 gallons. A larger pool needs more proportionately more Borax to achieve the same pH rise, etc. However, if you are starting at a different TA or pH, and you probably are, then the pH rise will be different which is why I said I could tell you what it would be if I had your numbers. Nevertheless, nearly everyone goes by these rule-of-thumb rules and generally add half the amount they need and then see what happens an hour later (then add some more).

Richard