Hardness and TDS

[sdaggie]

I had my water tested at the pool store and according to them, my hardness is 316 and they suggested adding 3 qts Scale Inhibitor. I have a vinyl lined pool. Is this necessary? When I test with my Taylor kit I get around 200 but I don't regularly test that because I didn't think it was necessary with vinyl.

Also, the clerk was concerned with my 'TDS' which was 2,200. Is this something to worry about?

Thank you for any insights!

 

[JoyfulNoise]

None of that should concern you at all.....standard pool store sales tactics.

My water has a calcium hardness of over 1200ppm and I can easily manage my plaster pool without getting scale. In a vinyl pool, calcium scale is very rare unless water balance gets wildly out of control (high pH, high CH and high TA). Can you post a full set of test results from YOUR test kit? Then it will be easy to tell where you saturation index is at.

As for TDS, that is simply a reflection of all the chemical components in your pool (calcium, stabilizer, salt, etc) and is mostly meaningless. You have a chlorinated swimming pool and chlorine eventually turns into chloride (salt) which then shows up in the TDS. It is not at all uncommon for chlorinated swimming pools to build up salt levels in the 1000ppm range over time and even as high as what is found in salt water generator pools (~3500ppm) if the water is not regularly drained and replaced with fresh water. So, no, TDS is not important.

 

[sdaggie]

Thank you for the information!! That was the only time I've had PS test this year - I am completely BBB and love it! My levels per my kit:

FC 5.5 (I added bleach this morning to bring to 8)
CC .5
PH 7.6
TA 125 (still high from PS bad advice 2 years ago)
CYA 80

 

[domct203]

Thank you for the information!! That was the only time I've had PS test this year - I am completely BBB and love it! My levels per my kit:

FC 5.5 (I added bleach this morning to bring to 8)
CC .5
PH 7.6
TA 125 (still high from PS bad advice 2 years ago)
CYA 80

How did you get a TA of 125ppm, the test reads in 10ppm increments.

When I plug your numbers into Pool Math I get a CSI of -0.02 at 84F. No worries of scale there.