White Calcium Flakes in Pool

[pattay712]

I balance my water every Saturday and didn't notice this last week. I saw white calcium flakes on my pool steps this morning. Near one of the returns. I pulled one out, dropped muriatic acid on it, it fizzed and bubbled so I'm assuming it's calcium. I checked the water chemistry:

ph: 7.8
Alk: 85
Temp: 86
FC: 7
CYA: 50 (I put some more in this morning to raise to 70)
CH: 400
Salt: 3200

It's a saltwater pool. I checked the cell and there's no buildup. Any ideas? I added some acid to drop the ph to 7.2 to see if it would help.

 

[mknauss]

The flakes are from the SWCG. When it reverses polarity, it sheds them. Please fill out your signature.

How did you measure a TA of 85?

Track CSI in PoolMath. Keep it between 0 and -0.3 and your SWCG should not scale up.

 

[pattay712]

Filled the signature.

I used the K-2006 testing kit. When I hit 80, it started turning from green to red. At 90 it was bright red. So I guessed 85-90.

 

[mknauss]

With your test data, and a TA of 90, your CSI is 0.22. So you need to lower your pH to 7.4. Keep doing that and get your TA down to 70 or so and the flakes should go away.

Read - Trouble Free Pool on how to do the testing.