pool store says ch needed to prevent metal corroding?

[cynthialb99]

water levels
fc-3
cc-0
tc-3
ph-7.7
ch-140
ta-118
cya-40
copper-0.25
temp 76
24300 gallon inground vinyl

pool store says need to raise ch to 200 inorder to prevent corrortion from ruining my ladder and heater- copper levels keep rising (slowly) previous owner used frog- but why are they rising- could ch be affecting copper in heater?

 

[frustratedpoolmom]

Hi and welcome

That's pool store myth, your pool is vinyl so your level is fine, it won't hurt the heater or other equipment.

Low PH can cause the heater to corrode, allowing copper to enter the pool Was the PH low for extended periods?

Did you use any copper based algaecides or HTH Dual Action tablets which contain copper?

 

[cynthialb99]

previous owner used frog- ph was low for a short period of time- but copper # keeps going up as season progresses- eventhough ph has been fairly stable

 

[JasonLion]

Copper could be going up as some old sequestrant wears out. Sequestrant binds to the metals to keep them from staining. It can also prevent them from showing up on the test. Over time the sequestrant wears out, and the metals become active again.

It is also possible that you are adding something to the pool that contains copper. A number of HTH products contain copper as do a number of algaecides.