Calcium Scale or Crystals?

[Ps6fsu]

I have a new plaster pool that was finished almost exactly a year ago. So this is the first time opening after being covered for the winter. I had a local shop close my pool on October 7th and just took the cover off yesterday. Upon opening, I found what looks like crystals on the side walls. I also noticed a white dust on the floor. Both easily come off with the pool brush but want to make sure I treat correctly. At first, I thought I needed to raise calcium hardness but I'm reading conflicting information. Anyone have a similar situation? Just tested water (results below) so will be adding muriatic acid and getting chlorine levels up as soon as my equipment is put back together and running.

FC = 0
PH = 9
TA = 180
CH = 250
CYA = 100
SALT = 2600 ppm
Temp = 52

 

[Mdragger88]

Be sure to enter the temp in PoolMath so the csi can be calculated correctly. You can adjust the parameters to see how it will be affected.
Here’s some info on that

Calcium Saturation Index (CSI)

How is CSI calculated? Very simple – use our PoolMath tool. To ensure long plaster life and save money, click here to learn more.

www.troublefreepool.com

 

[mknauss]

Why Are Calcium Crystals Forming in Pools?

In recent years, calcium crystals have been forming during the winter at a higher rate in some newly plastered swimming pools. From the reports we have heard, this problem seems to occur more often in the northeast of the country. Apparently, pool builders, plasterers, and service techs involved...

www.troublefreepool.com

 

[Ps6fsu]

Why Are Calcium Crystals Forming in Pools?

In recent years, calcium crystals have been forming during the winter at a higher rate in some newly plastered swimming pools. From the reports we have heard, this problem seems to occur more often in the northeast of the country. Apparently, pool builders, plasterers, and service techs involved...

www.troublefreepool.com

Thanks. I had read this as well as the Orenda article so I was a bit confused on what to do. Is this occurring because the water is pulling calcium out of the plaster? Or is it calcium breaking out of solution and collecting on the plaster? My CH is around 250-275 so it's in normal range. I have what looks like plaster dust on the horizontal surfaces and the crystals on the vertical ones. I brushed the whole pool and it all seems to come loose. The auto vac bag fills up like every 20 min with all this (see pic). I'm currently trying to lower PH and TA but kinda tough with my local stores being out of muriatic acid right now.

 

[mknauss]

The high pH pulls calcium out of the plaster I believe is the theory. Happens with new plaster that is not fully cured when closed for the winter.

Get the crystals out and maintain the pool as per the Recommended Levels

 

[Ps6fsu]

So I brushed the entire pool and got almost all of these crystals off. Then manually vacuumed them up. Had to empty the pump basket about 4 times. I then backwashed the filter. For what it's worth - I did pour some muriatic acid on the crystals and they fizzed quite a bit and melted. Now time to get my PH under control.