Blue scale in salt cell

[Sendero]

I installed a Hayward Aqua-Rite low salt generator in my pool in June of this year. Yesterday the “check cell” light was flashing so I took it out for inspection. The plates in the cell had quite a bit of light blue scale some of which was a good size. I should note that the previous Hayward SWG it replaced never had any scale buildup at all.
I tested the water today, the results are below. I add nothing to the pool except chlorine occasionally & muriatic acid.
FC- 4ppm
PH- 7.7ppm
TA- 80
CYA- 60
Calcium- 90ppm
Salt- 2100 ( a little high, recommended 1800ppm)
Does anyone have any idea what this might be or what caused it?

 

[mknauss]

Your data does not imply scale should occur but I do not know if the low salt version makes a difference. Typically, by lowering the TA, you should reduce the amount of scale created.

Blue color implies copper in your pool water.

 

[mknauss]

Try some acid on the piece of scale. See if it fizzes violently or just some.

 

[Sendero]

I put the piece of scale in the acid & it fizzled a little & dissolved slowly . I think the fellow who opened the pool back in April added some algaecide with copper but I thought it would have dissipated by now.

 

[mknauss]

Copper does not dissipate. It is in the water until you drain it.

Sounds like a calcium silicate or other calcium compound.

 

[Sendero]

Thanks. Good to know about the copper. Living in the Great White North the pool will be only be open for another 4 weeks max so I’ll see how much scale has accumulated at closing.