Cloudy Pool Water With Algae And Phosphates

by Joanna
(SW Ontario Canada)

Our winter cover broke this year and our water was greeny/brown. I used the usual opening kit and the water went cloudy.

It has been cloudy ever since (mid May). I have had the water tested on several occassions. I use Bromine and it is at a good level. pH and alkalinity are at the bottom of acceptable and calcium is okay.

My phosphates were at 2500 so I used a reducer which brought it down to 1000. I've had two suggestions to get rid of the cloudiness.

1. Add a 'commercial grade' phosphate remover and if it doesn't clear it use a clarifier

2. Another pool place tested for algae and said we needed to treat this to clear the water.

I have no visible algae but when I add the weekly does of algecide it turns the water cloudier. My pool is above ground, 40K litres.

Thanks for the question Joanna

It would be great to have your exact chemical readings. And be sure you're using a quality pool test kit. I've always used and recommend a Taylor FAS-DPD K-2006 test kit.

Green pool water is normally a sign of lack of a sanitizer. Honestly, a bromine is normally reserved for either hot tubs or indoor pools.

The pool is exposed to sunlight and the bromine gets degraded. Not as fast as chlorine without CYA, but faster than chlorine with CYA. The bromine gets converted to bromide, the bromide can get back to bromine by adding a chlorine shock. You can add a non-chlorine shock, potassium monopersulfate, or a regular chlorine shock.

In my opinion a bromine pool is a bit more expensive to maintain than a regular chlorine pool and degrades faster because there is no stabilizer (CYA) in the pool. You would still need to shock to
reactivate the bromine.

It's my understanding that pool water cannot be shocked with bromine. A non-chlorine shock is needed to kill extra bacteria.

It's basically this; phosphates are food for algae, but a properly maintained pool with a sanitizer level between 1.5 - 3.5ppm will kill the algae. 4-6 ppm for a bromine level.

If there's no algae, and phosphates are safe to swim in, what does it matter what the phosphate level is? I saved the YMCA nearly $5000 in the first year I was there because they we going through about 3 bottles of phosphate remover per week.

Each bottle was $32. I said it's a waste of money and time and ended it. Algaecides are used for preventative maintenance only. It can't get rid of nor kill algae. What kind of algaecide was used and did it have any metals in it? Many times copper is used.

If you're going to use an algaecide, get one that is a PolyQuat 60. This contains no metals and is safe for vinyl liners. You may not have a vinyl liner but other visitors that see this post may. There could be many reasons why your water is cloudy.

In general, a good shock and filtering 24/7 is the first step in clearing up cloudy water. You're probably going to get mixed opinions about what to do from me and your local pool store.

While I can't speak for them, I can say that I've personally cleared up hundreds of pools in Arizona, installed and cleaned dozens of filtration systems, and vacuumed for literally thousands of hours when it was 110 degrees. And I've been the pool operator for our YMCA salt pool (80,000 gallons) for the last 3 years.

Hope this helps and have a fun and safe swimming season.


Comments for Cloudy Pool Water With Algae And Phosphates

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Jul 27, 2015
Phosphate Treatment
by: Jerry

How long should a pool be closed when phosphate treatment is needed. Clubhouse pool is closing for 4 days. Seems an excessive amount of time.

Thanks for the question Jerry. I would first ask what's the phosphate treatment? My concern is that you, or someone, purchased a large amount of expensive phosphate removers. Here's a video about phosphates:

Phosphates are food for algae but phosphates are not one of the parameters associated with pool water maintenance. When the FC is kept at the right level in relation to the other readings there's no need for a phosphate remover. To answer your question, your pool should not be closed at all for a "phosphate treatment".

If you feel your situation is more complex than this, I do phone and/or SKYPE consultations. It makes things go much faster and many people have found it extremely beneficial, saving them time and money in the long run. All your questions will be answered. I have nothing to sell you so you know I'm not bias. If you purchase a personal phone consult you'll get all 3 eBooks for free.

Pool Consultation

Clear Blue Pool eBook

How To Clear Up A Green Pool eBook

Swimming Pool Resources


Jan 18, 2015
What Can I Do To Clear Up Our Cloudy Pool Water?
by: Anonymous

Our pool is cloudy. You can see the bottom but it is not clear.

Chlorine level is 1.5 and ph is 7.2.

What can I do to clear up our water?

Thanks for the question

Unfortunately due to the lack of information, it is difficult to say with any degree of certainty what might be causing your cloudy water. It could be dozens of different reasons:

Cloudy Pool Water

I need things like:

Full chemical readings

Your filtration type

How long has it been cloudy?

If you've used any flocs, algaecides, metal sequestrants, etc..

Do you have city or well water?

How long do you run the filter?

Have you back washed or cleaned the cartridges? How often?

Have you done anything to clear it up? If so, what is it? And what were the results?

How big is your pool?

Without this and more I simply cannot give you a reasonable answer. Contact me again and give me more details and I'm sure I can help. I'm going to merge your question with this one:

Cloudy Pool Water With Algae And Phosphates

You can find it on the Q&A page in the "Cloudy Water" category.

Swimming Pool Questions and Answers

Hope to hear from you soon.


May 19, 2013
Cloudy Water After Using Ascorbic Acid and Metal Free
by: Terry B.

I opened my pool a couple weeks ago (around May 1st) and the water looked really good for sitting since Last October. I had one of those winter pills over the winter and when I opened all of my levels were within range using aqua check test strips.

However, after I vacuumed the pool and got rid of the debris I noticed a lot of brown stains that would not brush off. So I used some vitamin C and it came right off. So I went to friendly local pool store and bought some stain remover (ascorbic acid). It took away the brown stains like magic.

I did that they talked me into adding metal free 24 hours later. The water was just a little cloudy.

At that point I noticed my chlorine level was getting pretty low. I did not want complicate the issue so waited another 24hours and when I shocked it the chlorine was non existent. I added some ultra bright clarifier and without really thinking about it I added some Clear Perfect, an organic clarifier. Well within an hour I had some really really cloudy water.

My chlorine seems to staying and using my test strips my levels are all within range. Of course the pool store wants to sell me some stuff called pool first aid and phos free.

Would it really be just better to keep shocking and backwashing? Any advice would be welcome.

Thanks for the question

I need a full list of your chemical readings. Something is going on and the readings will tell the story. Chlorine, alkalinity, pH, calcium hardness, metals, and stabilizer level.

Do not add any more clarifiers, pool first aid, or phos free. They only cover up the problem and won't give you a solution. They're pretty much a waste of money.


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