Milky water


New member
Jun 28, 2010
Dallas, TX
We've had the pool for 5 years, no problem until recently.
Water had been clear and nice. A few weeks ago it started getting milky (no algae, just kinda milky blue-white).

Took sample to LPS (local pool store) for analysis (no, don't have test kit, getting one TODAY).
Their report:

They told me to shock it. Used 5 pounds of Ca-Hypo (sorry, THEIR advice, again I'm new to group). Water got REALLY cloudy. LPS guy said "That's because it is reacting with organics".
At night and in morning FC= 3, by mid morning FC=0 and TC=0.
Water eventually clears some, but with FC=0 LPS says "shock it more", I shock again and it clouds again.
The pool itself is beautiful (ZERO algae), but the water just doesn't sparkle - at times it is pretty milky.
Also can't seem to get any residual FC for any length of time.
LPS was thinking that CYA was too high, tying up Cl, suggested a partial drain and fill.
Looking at the TFP site, it suggests that with a lot of direct sun, I might need even more CYA.

Two more bits of info: pool gets LOTS of direct sun and water's been REALLY warm (as high as 97° - I said lots of sun). I also noticed after a cloudy cool day yesterday, this morning the pool temp has dropped to 91 and water has cleared.

Here is what I'm thinking: Pool is actually pretty clean (biologically), but with the high temperature the CH and Ca-Hypo are combining to form a calcium salt, which is clouding the water. Meanwhile the sun is cooking my FC.

I shocked the pool this am with 5 gal of Na-Hypo (bleach) and will switch to Na-hypo from now on.
Anyone know of a cheap source of bleach in the north Dallas area, let me know!

Any thoughts/ideas/recommendations?


NSGS said:
Any thoughts/ideas/recommendations?
First; welcome to the 'page! Now:

1. Get some bleach in that pool!
2. Get a good test kit!
3. Quit going to the Pool Store and listening to them (and don't buy anything from them!)
4. Go to Pool School at the top right of the 'page.

You'll do fine if you read Pool School and get accurate water chemistry levels (don't trust the Pool Store, and once you get your test kit you'll have those!). It will be simple and easy, so don't be afraid!


Mod Squad
TFP Expert
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In The Industry
Apr 1, 2007
Sebring, Florida
Welcome to the forum. :lol:

I think you may be diagnosing pretty accurately about the CH and the Cal Hypo.

Even though your within limits on CH, when the Cal Hypo is introduced you get local areas of oversaturation and the calcium precipitates out. I'm not sure iof the increased temp would exacerbate that condition or not.

I would suggest lowering the pH down to around 7.2....that'll make it less likely to precipitate.......and to stop using the Cal Hypo altogether.....just use chlorine.


New member
Jun 28, 2010
Dallas, TX
Thanks for the thoughts (and welcome) - Wish I had found the forum a few years ago.
Re: temperature: I noticed that with the chemistry numbers punched into the "Pool calculator" the pool is "in balance" in the low 90°s but as the temperature goes up, I get closer to the "potential for scale" range. I think the "milk" is an indication that I'm approaching saturation - dumping in 5 pounds of CalHypo sure isn't the direction to go then!.

Good thought about lowering pH some, especially for the long hot summer ahead. I think next spring, I'll check the chem and if CH is still high maybe do a 1/3 drain-refill.

BTW, after shock of 5 gal of 6% bleach this morning (and a "cool" night and day that dropped pool temp to 91°) water is sparklingly clear and FC level is stable.
Definitely going to stop with the Cal-Hypo!!

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