New dark plaster and white specs in deep end after adding calcium and salt

[dpoolman]

Have a 19000 gallon newly replastered black plaster pool. Calcium was low after original pool builder ended service at 150ppm added 16 pounds of CH (more to be added this week)and 160 pounds of salt all to the deep end brushed around the pool and few days later there are white specs that won’t brush away on the plaster. What could it be and how do I remove them?

Reading before adding above chems
Fc 1
Ph 9
Ta 30
Ch 150
Salt 2000
Cya 20

 

[mknauss]

How are you testing?
Very difficult to have pH of 9 and TA of 30.

 

[dpoolman]

How are you testing?
Very difficult to have pH of 9 and TA of 30.

Taylor k2005. TA was the only thing not tested this week but rather 7 days prior.

 

[mknauss]

It is not possible to measure a pH of 9 with the kit you have.

White spots are likely calcium chloride that did not dissolve and are stuck to your plaster.

 

[dpoolman]

It is not possible to measure a pH of 9 with the kit you have.

White spots are likely calcium chloride that did not dissolve and are stuck to your plaster.

You’re. Correct max is 8 on the kit. So it’s a bit of a guess. Regardless of ph. How can I get the calcium off the plaster?

 

[mknauss]

If it does not come off, you will have to use some acid to remove it. But be careful. The acid can damage the plaster. And if you have black plaster, it is very susceptible to mottling.

 

[dpoolman]

If it does not come off, you will have to use some acid to remove it. But be careful. The acid can damage the plaster. And if you have black plaster, it is very susceptible to mottling.

Would brushing be the first option?

 

[mknauss]

Would brushing be the first option?

yes.

 

[dpoolman]

yes.

Thanks for your help. What about dropping PH to like 5/6 then brushing,would this loosen calcium enough to help? These are in the deep end so draining isn’t an option

 

[mknauss]

No. Do not lower the pH.