Cloudy after brushing...Calcium on walls?

[ka8yiu]

I have a fiberglass pool, and I can wipe my finger across the walls and get a slight white residue on my fingers.

The day that I brush the walls, my pool is slightly cloudy the remainder of the day, but crystal clear all other days.

Test numbers:

8/23 - 0745

FC 10.5
CC 0.5
TC 11
pH 7.4
TA 60
CH 250
CYA 50

8/24 - 0800 (the day of brushing, but before it was brushed)

FC 9.5
CC 0.5
TC 10
pH 7.5
TA 80 (I added baking soda yesterday afternoon)
CH 250
CYA 60

I checked the CH AFTER brushing, vacuuming and cleaning the filter and I got 275, twice.

Is this just the calcium depositing on the walls, and is it any issue to worry about?

Kevin

 

[pooldv]

The test results here do indicate scale, but if PH is usually higher it could be scale. More here, Pool School - Calcium Scaling

 

[ka8yiu]

I am getting a CSI of -0.09. The CSI in Pool Math says for all pools, greater than 0.06 is problem for all pools. Since "[FONT=&quot]Less than -0.6 is suggestive of problems for plaster, tile, stone, and pebble pools.[/FONT]"does not mention fiberglass, I am reading it as not a real concern at this time.

 

[Mr Bruce]

Can you check the baking soda you added (have been adding?) to see if it says "activated" or anything like that?

 

[ka8yiu]

I see no indication on the bag of "activated." It is Arm & Hammer, 5# bag bought at grocery.

The issue is not new. It's been like that the 3 months I've been here.

According to Pool Math, hovering over the CSI does read "balanced".

 

[Mr Bruce]

The only other thing I can possibly think of is if the previous owner used dry acid to lower pH, I know that that adds sulfates and can weaken plaster. I know you are fiberglass, I assume it would be similar. I don't know how to test for sulfates, perhaps someone else will chime in.

 

[ka8yiu]

Well, bottom line is that it's not bad, just noticeable.

Tnx

 

[pooldv]

I am getting a CSI of -0.09. The CSI in Pool Math says for all pools, greater than 0.06 is problem for all pools. Since "[FONT="]Less than -0.6 is suggestive of problems for plaster, tile, stone, and pebble pools.[/FONT]"does not mention fiberglass, I am reading it as not a real concern at this time.

That is correct, negative CSI has no impact on FG or vinyl pools. Anything below 0 is good for your pool.