White-ish flecks on surface of pool


Active member
Nov 13, 2020
New Jersey
Pool Size
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-9)
I noticed some whit-ish flecks on the top of the pool. You have to look very carefully to see it. I just tested my SWG pool and got the following:
Salt 3000
FC 2.6
Alkalinity 70
PH 7.4
Calcium Hardness 160
CYA 40

Anyone know what this could be or what I should do? I thought it could be calcium buildup but my numbers aren't jiving with that.


Mod Squad
LifeTime Supporter
Jan 17, 2012
Evans, Georgia
Hopefully it isn't the beginnings of an algae outbreak, but based on your low FC level in relation to your CYA level it may be?

FC/CYA Chart

For your CYA of 40 you never want to be under 3ppm of FC. Ideally if you keep it between 5-7ppm that allows you to lose some chlorine during the day (which all pools do even if no one swims) and still be far above that 3ppm basement level.

We recommend a higher CYA level for SWG pools. I would suggest adding another 30ppm (10ppm at a time) and retesting level. Then refer to the CYA/FC chart for the recommended FC levels.

Did you bring up your FC to desired levels using liquid chlorine *before* turning the SWG on? Always do so and then let the SWG maintain that level. SWGs work too slowly to bring a pool up from Zero ppm to x ppm before algae takes hold.

If you think you've possibly go algae, or just want to rule that out, perform an Overnight Chlorine Loss Test (OCLT):
Overnight Chlorine Loss Test

Get some liquid chlorine in there fast! Also your salt cell is undersized for your pool. You either need to run the pump & SWG longer or augment with liquid chlorine.

Maddie :flower:
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