Help, large Calcium spots keep appearing and growing.

[Rokihunter]

I have a 15,000 gal SWG pool that was built early 2017. Besides the initial start up I only add acid and liquid bleach in the colder months. I use the TFP kit to test my chemicals.

Current readings.
FC 4
CC .5
CH 400
TA 80
And PH likes to stay around 7.8

How do I get rid of these spots and do I need to lower my CH?

 

[mknauss]

Those look like calcium nodules. Are they raised up from the surface of the pool?

Do a Search for Calcium Nodules. Review those threads and see if what you have is similar.

 

[ajw22]

Calcium Nodules in pools

What are calcium nodules? In swimming pools and spas, they are small mounds, bumps, deposits, or “slag” piles of calcium carbonate which are formed from material that has been released from the plaster. The small calcium nodules are rough to the touch, hard, and generally gritty. Nodules may...

www.troublefreepool.com

White Spotting of New Plaster Pools

The problem of plaster spotting has been an ongoing puzzle and controversy in the swimming pool industry for over three decades. The generally round, smooth-yet-unsightly white soft spots in new plaster pools have long been a source of contention among pool plasterers, and pool chemical service...

www.troublefreepool.com