Result?

[BStaveley]

June 2 FC2 pH7.0 TA100 Salt 2930 Temp72 water clear
pool calculator suggestion - added 6 kg salt and borax which I couldn't find so added pH+ according to directions on bottle (added mid afternoon)
June 3 FC 5 pH7.4 TA150 Salt 2700 Temp 68 water clear
why did the #'s change so much overnight. We did receive some rain during the day yesterday.
pool calculator add 975ml borax and 27 kg of salt - have not yet done.

 

[JasonLion]

The salt number is going to fluctuate. Even the better salt tests are +-400, so your results are well within the range of variation you would expect to see from the test even when the actual salt level is not changing at all.

The PH change is not surprising given that you added some PH +, and that would also account for some of the TA increase (PH + also increases TA, though not usually by this much). Also, PH is fairly variable and tends to drift up over time.

The TA change is surprising. Some of the increase would have come from the PH +, but this is more than I would expect. I suspect some kind of minor problem with testing. The TA liquid drop test is especially prone to electrostatic interference. Try wiping the tip of the dropper bottle with a damp cloth before starting the test.

Another thing to keep in mind is that the Pool Calculator doesn't really tell you what you should do, instead it tells you how to do something you have asked it how to do. The numbers in the target column should be adjusted depending on your specific situation, something it can't do for you. The PH is now acceptable. I wouldn't raise it any further. Your salt level is a little low (by either test result) so I would raise salt a little.

 

[BStaveley]

Thanks
The targets I have set for our pool are
TC 2
pH 7.5
TA 100
CH260
CYA 50
Sodium 3000
Does that seem appropriate?

 

[Richard320]

Thanks
The targets I have set for our pool are
TC 2
pH 7.5
TA 100
CH260
CYA 50
Sodium 3000
Does that seem appropriate?

The chlorine is the minimum recommended. That's too low. You want some breathing room so when someone gets in the pool all sweaty, you don't immediately dip below minimum. At the end of the day, when the sun's gone and the pump is off and everyone's done swimming, you should still have at least 2.

If you go to http://www.poolcalculator.com/ and scroll waaaaay down to the last line in the table (it's yellow) you can select troublefreepools, vinyl, and SWG and it will place reasonable goals on the chart for you.

 

[BStaveley]

water clear
temp 70
Salt 3500
FC 5.5 - had been higher earlier but turned off salt generator x 24 h then restarted at lower rate
cc - o
Ph 7.6
TA 140

I took a water sample to the pool store just for comparison, their results showed,
TC 6.3
FC 6.3
pH 7.9
CYA 30
TA 135
Ca 118
Borate 45
phosphate 300
They are suggesting adding salt (I'm okay with that); shocking the pool and putting something in to lower the PH
Appreciate any thoughts or suggestions.
Thanks

 

[Richard320]

water clear
temp 70
Salt 3500
FC 5.5 - had been higher earlier but turned off salt generator x 24 h then restarted at lower rate
cc - o
Ph 7.6
TA 140

I took a water sample to the pool store just for comparison, their results showed,
TC 6.3
FC 6.3
pH 7.9
CYA 30
TA 135
Ca 118
Borate 45
phosphate 300
They are suggesting adding salt (I'm okay with that); shocking the pool and putting something in to lower the PH
Appreciate any thoughts or suggestions.
Thanks

Trust your own numbers. Which means pH is fine. And they always recommend pouring in a bag of magic powder every week at least. Ignore that, too. You obviously have no problem with the SWG working, so salt is probably okay. Do you see a pattern?

What did you get for CYA? Is it at your target of 50, or did you raise it to 70ish because of the SWG?