How much is the TDS increased if Borax is added to 50 ppm in a 9000 gal pool?
Looking forward to your replies.
Aloha
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How much is the TDS increased if Borax is added to 50 ppm in a 9000 gal pool?
Looking forward to your replies.
Aloha
You shouldn't need to worry about TDS. When you add 50 ppm Borates (via Borax) to your pool AND add enough Muriatic Acid to restore the pH, the TDS increases by about 417, but much of this increase is with neutral Boric Acid, B(OH)3, so only an increase of about [EDIT] 139 [END-EDIT] will register on a conductivity meter (mostly as sodium from the Borax and chloride from the acid you need to add to lower the pH since the Borax raises it). So, the added TDS is just salt and Boric Acid, which is nothing to worry about.
If you are using the spreadsheet to calculate CSI and other parameters, you'll notice that the increased TDS barely nudges the index so is nothing to worry about.
Richard
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.
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
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
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).Quote:
Originally Posted by smallpooldad
Richard
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
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.
Catnip,
I agree a stainless steel brish works better.
Aloha
Well it was not black or mustard algae.
Chlorine remained stable over night, for 3 days, at 40 ppm, pumped it back up to 40 ppm every night for 3 nights. So me thinks maybe adding Yellow Treat (Sodium Bromide) will do the trick, as these two types of algae are thought to be chlorine resistant.
Added 5 oz of Yellow Treat and pretty much nothing happened. Chlorine got used up and went down to 30 from there it has been a very slow descent to 12 ppm of chlorine. At 12 ppm of chlorine last night and 12 ppm chlorine this afternoon at 3 pm, it has been very overcast and humid today and yesterday.
The stains were primarily lightened when I initially added Borax, and then when I scrubbed with a wire brush. However, since then really no change still some light stains in the plaster maybe from 9 years of not knowing the Pool Forum. Why did you not call me in those 9 years?
The Borate is around 70 ppm and this is why the chlorine stubbornly refuses to go down any faster. What are your opinions?
If that is the case, I will report back, and then maybe Chem Geek you have found the answer to controlling chlorine use.
Chem Geek, if this is true then be careful if you see any guys dressed in black suits with violin cases and wearing a yellow Wal-Mart smock!
Finally the pool is crystal clear, clearer than it has ever been.
Here are the figures:
Cl 12 ppm
Alk 80 ppm
pH 7.4 ppm (seems to be stuck at this number/has not moved for days and yes I neutralized the chlorine for a good reading)
Calcium 350 ppm
CyA 50 ppm
TDS 740 ppm
Aloha and thank you one and all.