Milky blue water after Phos-Free

For the first time ever, my pool has been crystal clear almost from the time I opened it -- and then a water test said my phosphates were over 1000 ppb. NO visible algae. I was advised to use Phos-Free, and did so - following instructions on the bottle & on their website to the letter. After 5 days, pool still crystal clear, I cleaned my cartridge filter. Chlorine was very low and I added what I would usually add every week. Instantly the water turned milky blue, and has stayed that way for more than 24 hours.

What happened? Pool store says this is probably dead algae and if it doesn't clear, they advise using clarifiers. I feel like I was advised to fix something that wasn't broken.

Before doing anything else, I'd appreciate any some advice. thanks.

Sorry this happened to you. Moral of this story -- stay out of that pool store. Pool stores exist to make money selling you things whether you need them or not.

-- Do you have a drops-based test kit? If so, what kind? Post some current numbers.
-- What kind of pool is this and what is the volume?
-- What is the source of your fill water --- a well or city water?
-- What all have you added to the pool, meaning ingredients and not just product names.
-- What size is your pump?

thanks for the quick response, Watermom. I'm hoping the water will clear on its own - seems a bit clearer than yesterday, but that may be wishful thinking.

I've been using AquaChek strips to monitor pH & chlorine, with pool store tests a few times a year. Right now the strip says free chlorine is 5 ppm; pH is 7.8; alkalinity is about 150; stablilizer is 30-50 -- all good.
This is a 100,000 litre vinyl pool filled with city water. I have a Pentair Clean&Clear cartridge filter and a 1hp hayward pump running 12 hrs/day. (I did fill out the pool chart, but I just joined this forum today & don't seem to be able to see it again.)
This year, all I've added is chlorine (hth ultra & pucks in the chlorinator); sodium bicarb (Alka-plus), and now the Phos-free.
My pump is 1 hp, run 12 hrs/day.

We call them 'guess-strips' for a reason. Go to Walmart and see if they have the HTH 6-Way drops-based kit (not the 6-way test strips!) and get that. Test your water and post your readings. Keep your pump running 24/7 while you are trying to clear it.

Quote:

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Originally Posted by Electralily

I was advised to use Phos-Free, and did so - following instructions on the bottle & on their website to the letter. . . . Instantly the water turned milky blue, and has stayed that way for more than 24 hours.

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If you've not had any green . . . it's not algae, and the pool store knows that.

I'm not sure on the time line of the events you describe. If it turned after you added the PhosFree, then that's the problem. It's pretty standard for phosphate removal products to cloud a pool; it doesn't always happen, but it happens often enough that either (a) your pool store is filled with ignoramuses or (b) they knew and lied to you.

Chem_Geek has played around with this some, and has found that there at 2 clarifiers that seem to help:

GLB Clear Blue
BioGuard Polysheen

Other products may work, too. But without testing we don't know, since all clarifier ingredients are 'secret'.

This phosphate remover is cheaper and more effective than PhosFree, and seems not to cloud pools as much:

Clorox Phosphate Remover

I've used it, and seems to be slower acting than others -- you may not see a reduction in phosphates for a week. That may be why it seems not to cloud pools as much.

BUT, keep in mind that low phosphates do NOT kill algae. Low phosphates make it EASIER to kill algae with chlorine, but if you don't maintain your pool chemistry you will STILL have algae.

I'm also seeing some evidence that the phosphate test kit that Natural Chemistry supplies is inaccurate. I'd recommend getting the Taylor kit => http://pool9.net/tk/


Anyhow . . . membership upgraded.

Thanks Ben. Re timeline: the pool did not cloud with the addition of Phos-free. It was crystal clear when I added the product, and stayed that way for 5 days after. The Phos-free instructions are to run the filter for at least 48 filter hours without cleaning off the product and to keep the chlorine under 5 ppm, so I didn't add chlorine for several days. Then, after cleaning the cartridge filter I added my usual weekly 2 scoops of hth, and the water immediately turned opaque. It's been two-and-a-half days and the water is very slowly clearing. I can make out the bottom of the shallow end. I'm hopeful it will clear eventually without clarifiers. I don't plan to do this again, and I have ordered a Taylor kit.

OK.

That's different. Immediate clouding after adding HTH is almost certainly calcium carbonate precipitation.

1. FIRST, make completely SURE that there is no feeder, mineral device or other chemical or treatment gadget or gizmo anywhere between the skimmer and the filter.

2. SECOND, make SURE that there is NOTHING the skimmer basket.

3. THIRD, add HTH directly to the skimmer, but in 1/4 the normal dose. Watch the pool return, to make sure there's no cloud going back into the pool from the HTH. So long as there's not, add the rest of your doses to the skimmer, 1/4 dose at a time, waiting at least 15 minutes between doses.

4. Watch the Taylor vids: http://pool9.net/tk-guide . When you get the kit, be careful to get an accurate TA and CH test result. Ignore the booklet and blue wheel.

Good luck!

I just want to close the loop on this case of milky water. In the end, it was confirmed that PhosFree did NOT cause the milky water - it was the dry chlorine - HTH - causing calcium carbonate precipitation, as predicted by PoolDoc / Ben. So, I didn't add any clarifiers, I'm back to liquid chlorine, and have a crystal clear pool again. Thanks so much for sharing your expertise!

Thanks for the follow up!