pH and T/A rose significantly after Bo treatment

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taekwondodo

taekwondodo

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Apr 26, 2009
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So - curious where the additional T/A came from to lift my pH to almost 8 over the last couple of weeks.

Date 05/10
Time 8AM
FC 9.0
CC 0
Alk = 80ppm
pH = 7.2

After that, I did the Bo Treatment.

Today (8/5)
FC= 6.0
pH=7.6 (down from ~8.0 via 4 Gallons HCl over the last few days)
T/A at ~140-150 - has hardly budged with the recent acid additions and running the falls for 4-6 hours/day...


<edit> FYI - I did check the fill water - have added about (est) about 4-5K gal to cover evap over the last couple of months - fill's T/A is around 200... this may explain a small rise, but not 70ppm.
 
If you mean you added borates to your water then you did something wrong. Borax will not cause the TA to increase by that much (although it wil cause a small net increase in TA, however it is not carbonate alkalinity but borate alkalinity so it does not really contiribute to pH rise from outgassing of CO2) and your pH should not have been abouve 8.0 when you were done if you added the acid correctly as you did it (as outlined in my howto).
so-you-want-to-add-borates-to-your-pool-why-and-how-t4921.html
 
Well, I followed it to a "t"...

Readings a few days before the Borate treantment:

Date 05/12
Time 9AM
FC 6.0
CC 0.0
Alk = 80ppm
pH = 7.2
CYA = 40ppm.

Readings three days after the Borate treatment:

Date 05/18
Time 6PM
FC 6.5
CC 0.0
pH 7.2
T/A 75-80ppm

Its a shame I haven't been religiously tracking T/A since then, just Cl, and occasionally pH.

Thanks,

- Jeff
 
ha...I just realized what you are asking...are you asking why your TA increased to 140 over the past 2-3 (may - Aug) months since you added borates? If so, I think you partially answered that with your fill water TA...perhaps you've actually replaced more water than you think...also have you added any baking soda or soda ash (PH+)
 
Even if I would have added 22.5Kgal of fill, the reading would not be ~140-150.

80 (50%) + 200 (~50%) =280/2=140... I know I haven't added 22kG. I add about 1-1 1/2 inches a week. Over 8 weeks, that's about 12", or ~5Kgal...
 

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OK - so I think I can explain some of the rise...

Now that the pool is so darn purdy, something that was frustrating the heck out of me was that underneath one of the falls, there was SIGNIFICANT calcium deposit build-up on the tiles below the stone. I'm talking about 1/8" to 1/2" (1/2" was the extreme) build-up that had been there since the first year.

Before the season started, I got rid of some of it with MA and it would bubble and boil and fizz and slowly dissolve, but I could never get any under the falls because it was too difficult to pour acid there. Well, now that the pool's all shiny and the best its looked since it was new, I climbed in last weekend with a screw-driver and "chipped" and scraped all of that white stuff out from underneath the falls.

IIRC, this calcium left over from when the falls were built is actually calcium carbonate! I never noticed any of it dissolve in the pool water, as most of it went to the bottom and was vacuumed up by the next day.

BUT - from aquaria, I also know that CaCO3 doesn't dissolve as readily in water as NaCO2... so may explain some of the rise...

So, I guess, unknowingly, maybe I did add something to the pool - but not more than a few pounds of it could have dissolved.

Oh - and the tile looks brand-spanking new under the falls now.
 
reebok said:
the first results he posted in his first post are before borates. the ones with a date of 5/10 and the sentence below says "after that I did bo..."
Click to expand...
Oh, I did miss it then... :mrgreen:

I was just going to say that my TA also rose more than I expected after adding borates, but nothing like the OP's of course. Funny thing, I keep hearing of how difficult it is to adjust TA after adding borates, but my pool doesn't seem to follow that rule. It seems to move about the same as before...
 
Beez said:
Funny thing, I keep hearing of how difficult it is to adjust TA after adding borates, but my pool doesn't seem to follow that rule. It seems to move about the same as before...
Click to expand...
Same here. I have never noticed a difference when needing to lower the TA a bit. However, when you need to move it a lot it goes a bit faster before borates. I stress getting the TA in line first because I assume that a lot of people will skip that step because it's 'too much work' and getting the TA in line is nedded for pH control.
 
Possibly just pH requires more acid than before? I know my spa needs more acid to move pH now that I have borates in it (but requires adjustment far less frequently). I haven't really been watching the TA.
--paulr
 
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