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

[catnip]

Richard, I've seen several posts that indicate your spreadsheet is available and being used by others on this forum? Is this true? I've searched but can't find a reference / download location. Thanks.

[chem geek]

A couple of items. First, adding 50 ppm of Borates also increases the TA by 6.1 ppm. However, the buffering of pH from Borates is more than would be implied by this small TA increase because most of the Borate "buffer" is in the form of the neutral Boric Acid species that does not get reported in TA. Technically, at normal pool pH, the Borate buffer is more effective at resisting a rise in pH than a lowering of pH while the Carbonate buffer is the opposite, though the Carbonate buffer is closer to being equal in its resistance in both directions. The TA only measures the buffering capability to resist a lowering in pH (i.e. to resist acidic changes) and does not measure any buffering capacity to resist a rise in pH.

As for the spreadsheet, it may be found at the end of the first post in this thread in The China Shop under the heading "Spreadsheet for Detailed Calculations" where there is a link called PoolEquations.zip

This spreadsheet is in The China Shop for a reason. It is very complex, highly technical, and will scare away vampires. Nevertheless, if you ignore the lower part of the spreadsheet where the detailed calculations are performed and ignore all the chemical equations in the descriptions, it might be OK to use. There are no instructions with it and it is not designed for public consumption. My plan was to someday try and distill into simpler though somewhat less accurate formulas some of what is done so that it could be included into Michael's BleachCalc (he already has a lot of it -- though his acid/base calculations are only accurate at a fixed "typical" starting pH and TA) and also into a simpler spreadsheet form for Mac users (since BleachCalc is only for the PC). This is a large task that I have not gotten around to yet.

Richard

[smallpooldad]

Chem Geek,

Thank you, and yes you were correct I did have some (maybe lots according to the Chlorine usage) black and mustard algae which the chlorine is eating at an alarming rate.

My credit card is now up to over $50 for Wal-Mart's Ultra Bleach. I keep going back there so often they are beginning to look at me strangely. The plaster is beginning to look like the day it was put in, although the pool is still cloudy. Maintaing the level at 40 ppm. Did have to use a stainless steel brush to break it up as the nylon did not work; lost about 10 lbs scrubbing my little pool in full sun, would hate to do this to a larger pool.

Will let you know the full story once it is over; summize several dozen Ulta Bleach bottles more!

Aloha

[chem geek]

Thank you, and yes you were correct I did have some (maybe lots according to the Chlorine usage) black and mustard algae which the chlorine is eating at an alarming rate.

Well, keep at it. Remember, patience, patience, patience. Also remember that the chlorine loss during the day isn't the thing to look at since that's due to sunlight. It's the overnight loss that is key -- and of course seeing how your pool clears up. The cloudiness will go away as your filter removes what was in the pool. You might need to clean your filter (backwash if sand or DE -- spray clean if cartridge) if you had lots of this algae in the pool (you can monitor your filter pressure to see if it has gone up due to the filter capturing this algae).

Richard

[smallpooldad]

Chem Geek,

Will do, have backwashed it once for two and half minutes of whitish-grey powder. Patience you say don't you remember I am half-German, that word is not in our vocabulary

Getting dark in an hour so will pump up the chlorine and check in the morn. Hope that it will be the same; if it is, sell Wal-Mart's stock, as I will not be shopping there for a while!

Aloha

[catnip]

Richard, thanks for the pointers on the spreadsheet. I presumed it would be complex, but your very lucid explanations of what seems to be happening with pool water has rekindled my long-lost chemistry interest (lost after too many late evenings studying for quizzes). I'll use at my own risk!

smallpooldad, I've found that directly applying (rubbing/scrubbing) tri-chlor onto black algae patches seems to work quite well. And I've been using a stainless steel brush on mustard algae with good success also; the stainless brush seems to work better than a synthetic bristle brush.....but just my experience.

[smallpooldad]

Catnip,

I agree a stainless steel brish works better.

Aloha