Problem with TA, CH, and CYA

[blazer58]

I cannot seem to keep my TA, CH or CYA in check.
This spring we drained the pool, cleaned it and refilled.
Since then I cannot get TA in check, or CYA and CH up

Readings...
Temp 84
FC 6.0
CC 0
PH 7.6
TA 100 ( TA runs high but usually around 80)
CH 200
CYA 60
Salt 3700
CSI -.23/-.27

Early June we had the heater on and water temp was staying 88/92
This past weekend PH was 8.2 so I lowered to 7.6, turned the jets up to face the surface to aerate the water and we did alot of splashing for two days while swimming
In stages over the past 4 weeks, I have added 20 lbs of CYA, and 150 lbs of cal chloride
My plaster needs recoating , but thats another story

Should I tweak anything or are readings ok

 

[Jimrahbe]

58,

Just leave your TA alone..

Tell me why after lowering your pH to 7.6, you started aerating and splashing around?? This will drive pH back up, so I am puzzled as to what you were trying to do?

20 lbs of CYA should add about 70 to your CYA level.. Was it zero when you started? How long after you added it did you try to measure it? How did you add the CYA to your pool?

Thanks,

Jim R.

 

[Richard320]

Easiest first. 20 lbs of CYA in 35000 gallons should bring it to 68. Given the vagaries of pool volume and visual testing, and allowing for some losses to splashout, pumpout for rain, or backwashing, and the normal breakdown over time, I don't think there's any problem with the CYA. If you want to raise it to 70, just add some more.

80-100 TA is fine. What number were you targeting?

The CH is low. So's your CSI. If you try running a lower pH and/or TA you're going to damage that plaster even more than it already is. What you've added should raise CH higher than you're testing. Questions for you: 1) Is it possible you're using the wrong multiplier for the sample size. You wouldn't be the first. 2) Have you been slacking on pH adjustments for long periods of time causing scale to form? That is, do the walls feel like you're growing sandppaper? Could be patches that look blue-grey or tan, not just pure white.

 

[blazer58]

Sorry for late reply, had to leave for work.
Trying to get my TA to around 80. and I thought lowering PH, and aerating was the way to lower TA.

I norm run my CYA low, but with having a SWG this year. was targeting 70, and with what I have put in should be at 70/80.
I know test is easy to read wrong, so will assume its 70 I guess.

As far as testing, using correct sample size and correct multiplier.

I check PH twice a week, and do not have to add acid very often, I do not notice/see any scaling

guess my main concern is not wanting to trash my new SWG with low CH and a low CSI reading

 

[Jeff J.]

Aeration raises PH without affecting TA. The only way to lower TA is to add acid. But from what I've read on here, fiddling with TA is not usually necessary unless you are having PH problems. Read Pool School on water chemistry.

 

[Richard320]

Sorry for late reply, had to leave for work.
Trying to get my TA to around 80. and I thought lowering PH, and aerating was the way to lower TA.

I norm run my CYA low, but with having a SWG this year. was targeting 70, and with what I have put in should be at 70/80.
I know test is easy to read wrong, so will assume its 70 I guess.

As far as testing, using correct sample size and correct multiplier.

I check PH twice a week, and do not have to add acid very often, I do not notice/see any scaling

guess my main concern is not wanting to trash my new SWG with low CH and a low CSI reading

Don't sweat the TA. Whether its 80 or 100 won't affect the swimming at all.
The CYA is probably testing correctly, as I mentioned. above. If you want to raise it to 70, add 10 ppm more.
The Calcium is still the worrisome one. I wonder how pure the stuff was. Could it have been ice melt that has a bunch of salt too? It should have pushed CH over 300, closer to 400 ppm. Low Calcium is fine with the SWG. But the plaster walls don't like it. You don;t want the plaster to start eroding, so that when you brush you start removing the surface.

 

[blazer58]

From old poolmath web page....
to lower TA you reduce pH to 7.0-7.2 with acid and then aerate to increase pH
I guess I should have lowered PH more, but will leave TA alone, as it norm stays on high side.

Ice melt was Joes (90+ % pure, and what has been recommend here before).
I too thought maybe it had salt in it, but it did not effect my salt level.
I added another 150 lbs of salt a week after adding the last batch of cal chloride

 

[Jeff J.]

From old poolmath web page....
to lower TA you reduce pH to 7.0-7.2 with acid and then aerate to increase pH
I guess I should have lowered PH more, but will leave TA alone, as it norm stays on high side.

Ice melt was Joes (90+ % pure, and what has been recommend here before).
I too thought maybe it had salt in it, but it did not effect my salt level.
I added another 150 lbs of salt a week after adding the last batch of cal chloride

What that means is that adding acid lowers PH and TA. Then when your PH is down to 7.0-7.2, you can aerate to raise the PH back up without raising TA, and repeat the process if needed. When your PH was 7.6 it was perfect, so no need to aerate.

 

[blazer58]

What that means is that adding acid lowers PH and TA. Then when your PH is down to 7.0-7.2, you can aerate to raise the PH back up without raising TA, and repeat the process if needed. When your PH was 7.6 it was perfect, so no need to aerate.

I read that wrong, Thanks for the correction, explains why PH jumped up a little so quick.