CLOUDY WATER & Chlorine Level Is Still Too High After Shock Treatment

by Sheila
(Pasadena, Texas)

We had a bad green algae problem (our pool is an above ground) 16'round 48" depth and I believe it is a little over 5,000 gallons. It is less than 7,000 I know for sure.

Anyway we treated the algae which like I said was bad, with 3-1Lb. bags of shock which it's not green too much anymore.

It's so cloudy I really can't tell.

We put a long hose on the intake valve with a wand and vacuum head and vacuumed and let the pump run and kept cleaning the filter as needed (a cartridge filter).

In the beginning the pH was way high and we had no chlorine showing on test kit.

Well now, we have excellent pH level. Now we are too high on chlorine, because of shocking I'm sure.

We put 2ounces of blue clarifier in, waited and added 2& 1/2 more ounces of clarifier.

It seems slightly better, but still real cloudy but it has only been about 1 hour since I added the last clarifier amount.

I still have pump running I want to get in and vacuum but chlorine level is still high on test kit.

Having said all this I quess what I want to know is how long till the chlorine level will come down after having to shock it so much for the algae problem, and how long can I tell if I need to add anymore clarifier to help clear up cloudiness.

Like everyone else, my kids want to get in the water and want to know how long?

It is very hot staying at 100 degrees during the day.

Thanks for the question Sheila

First, I'd tell you to keep filtering and cleaning out the cartridges once per day.

Next, lay off the clarifier for now. When the chlorine kills the algae, the pool water will become cloudy. This is where the filter comes in.

It will trap all of the dead algae so you'll
need to constantly be cleaning the cartridges.

You might want to get another set and swap them out for the dirty ones. Clean them, then swap them out.

Keep doing that until the water clears.

Chlorine doesn't cloud water. If it does, it's only temporarily because you may use calcium hypochlorite.

The calcium will sink to the bottom and can be vacuumed up.

I'd like to have your complete chemicals readings:


CYA (cyanuric acid/stabilizer)



Calcium Hardness

Metals (iron and copper)

Total Dissolved Solids

It makes troubleshooting much easier and the process of clearing up your pool will go much faster.

You can get this done at your local pool store.

Without these numbers I'm just guessing at what the problem is.

I'm not sure what "high chlorine" is. To some people it can be 5.0ppm and other 15ppm.

I'd encourage you to get a Taylor FAS-DPD K-2006 pool test kit.

Pool Water Testing

Water Testing Kit

It's really difficult to say exactly how long it will take the chlorine level to come down.

It depends on the level.

If it's at 20ppm it will take longer than if you have a chlorine level of 10ppm.

An educated guess, with the sun and 100 degree heat, would be about 2 - 3 days, but again, it depends on the level right now.

You have a couple of options immediate results. You can do a partial drain and refill. This will dilute the chlorine.

Or use a chemical called Thiosulfate. This is a chlorine neutralizer. Only use this in extreme circumstances because it may mess up the chlorine reading.

An 8.0ppm chlorine level is safe to swim in, but no higher.

To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Cloudy Water" category.

Swimming Pool Questions and Answers

Check back to this post for answers.

Hope this helps and have a great Summer.


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Aug 12, 2014
High Chlorine
by: Robert

Alright, we have the readings and I hope they're correct, so here we go. Again, you must take control of your pool and get the Taylor K-2006 kit. I have many videos on YouTube on exactly how to use it.

Next is the use of the Leslie's Algae Control. It's a PolyQuat 60 algaecide which is good but here's the deal; algaecides are used for preventative maintenance only, it's very hard for an algaecide to kill already existing algae. It can't kill the algae faster than it reproduces. Only chlorine can do that. By looking at your numbers you're on the verge of having green pool water, and this is why.

The pH is high, above 8.0 which means you're only using about 25% of your active FC. Then you have an extremely high CYA. The range is 30 - 50ppm. There's a CYA/FC relationship that needs to be met and the magic number is 7.5%. Your CYA needs to be 7.5% of your chlorine level. These videos go into more detail on that:

Pool chlorine too high -
What Are Problems With Swimming Pool Water CYA (Cyanuric Acid/Stabilizer/Conditioner)? -
When To Lower Your Swimming Pool Cyanuric Acid/Stabilizer/Conditioner -

The FC range is 2 - 4ppm. As the CYA increases through the use of tabs and heaven forbid you're using dichlor or trichlor for weekly chlorination, the CYA will increase quickly. For every 10ppm of chlorine added with Dichlor, you'll raise the CYA by 9ppm. For every 10ppm of chlorine added with Trichlor tabs you'll raise the CYA by 6ppm.

If you allow the CYA to get to 100ppm, you need to run the chlorine at 7 - 8ppm for the chlorine to be effective. When the CYA gets this high the only way to reduce it is a partial drain and refill. There's no chemical to reduce the CYA. If your CYA is at 100ppm, and the range is 30 - 50ppm, then by draining 1/2 of the water and refilling it you'll drop the CYA to 50ppm.

At a CYA of 150ppm you need to run the FC at 11ppm for it to be effective.

The chlorine remover you alluded to is probably thiosulfate. It's excellent at decreasing the FC but you may do it at the cost of the other readings. It can mess up the chemical balance. I used it at for the Y pool when I had to shock then bring down the FC quickly for the swimmers.

If the CYA is that high you have a couple of options. First is to keep the FC at 10 - 12ppm but that makes swimming a bit uncomfortable. 2nd, and you may not like this, but a 3/4 - full drain and refill would be in order. The most effective way is by dilution.

I would advise you to not put another drop of anything in the pool until you do a 3/4 - full drain and refill. I can almost guarantee that you'll be fighting a high FC and/or green pool water issue until the chems are resolved.

This is what I had to do with this pool. The CYA was at 100ppm. I did a 2/3 drain and refill, balanced the chems, and have only shocked the pool 2 times in 6 months and it's perfectly clear and balanced.

If you feel your situation is more complex than this, I do phone consultations for a donation of your choice. 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.

Pool Consultation

Hope this helps and have a great Summer.


Aug 12, 2014
High CL
by: Anonymous

Thanks so much for the reply. Yes, we are using the OTO kit. Algaecide was from Leslie Pools (14028 Algae Control). Computer analysis results (below) are from National Pool Supply and are as follows:
TC 10
FC 10
pH 8.1
TA 115
Ca 800
Stabilizer 150

I was told to ignore everything until I get the Cl in check and they wouldn't sell me any Cl remover because they said they didn't know how much I would need because I definitely had more than 10ppm of Cl and if I put too much then I would have a hard time getting Cl into the pool (I doubt that). I have talked to 3 different people at NPS and all said to drain the pool and wait. They also tested with the strips for me.

The Leslie person told me to shock the pool that I had no free CL based on his 10 second test (also with a liquid test - couldn't see what he was using - 5 drops of something).

Aug 11, 2014
Chlorine Over 10ppm
by: Robert

Thanks for the question. First I'd encourage you to take control of your pool and get a good Taylor K-2006 test kit. I've done a series of detailed videos. You can start with the chlorine one:

How to test chlorine -

Next is I'll need a complete list of the chemical numbers, the actual readings. Chlorine, CYA (cyanuric acid/stabilizer), pH, Alkalinity, Calcium Hardness, and Metals (iron and copper) and names of any algaecides you may have used along with clarifiers, phosphate removers, and/or flocs. It makes troubleshooting much easier.

I'll assume that you're either using the yellow OTO kit or test strips. These are alright but will never give you the numbers you need. Most pool stores can only test chlorine up to 5ppm.

Another issue may be an extremely high CYA but again I don't have that reading so it's just a guessing game.

I do know that chlorine cannot increase on it's own. If anything, it will decrease due to the sun, heat, UV rays, etc... Chlorine must be added to the pool to keep it at a certain level or increase.

Get back to me with the chemical numbers and I'm sure I can help.


Aug 11, 2014
Chlorine won't budge - over 10ppm
by: Anonymous

We had algae problem and shocked pool 2 months ago. All was fine. Tested the water 2 weeks ago and chlorine off the chart - orange precipitate forming during Cl test. Took sample to pool company and said it was over 10. Drained 2 feet out of pool (20% of volume)- no change.

It's been over 100 degrees for 2 weeks - no chlorine in it for over 2 weeks. Yet, Cl level still over 10. Total volume around 40,000 gallons. Added 3 gallons of peroxide to see if it would change at all - nothing... pH ranging around 8.

Took sample to second pool company and was told to ADD chlorine - that I may have high total Cl but no free chlorine. First pool company said definitely do NOT add chlorine.

Any suggestions?

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