Help with cloudiness and FC reading zero every other day

kmarcel

Member
Jun 20, 2017
10
Syracuse, NY
Hello, we are struggling to keep our 10x20 kidney shaped inground pool from losing FC. One day it will be reading 3ppm for FC and the next day it will be down to zero. My husband goes to the pool store 2 to 3 times a week (don't even want to know how much money he is spending there) and comes home with instructions to do this and that and the next couple of days it's the same issue. Yesterday pool was crystal clear and good chlorine readings and this morning it was cloudy with zero FC with no swimming. He shocked the pool today and a couple hours later the FC was about 1ppm and the CC was about the same if not a little higher than the FC, which I know is an issue. The CYA was between around 20, maybe almost 30. PH was 7.2ish. This is our 3rd year with this pool and we had the same problem last summer and I'm afraid we're going to go through it again this year. It's a small pool, only 5' deep, sand filter, vinyl liner.

We will leave the filter running all night since he shocked it early this afternoon. Not in sun, cloudy day and there is a fair amount of shade on the pool from trees, which also causes debris in the pool as well. Normally filter runs 8-10 hours a day.

My questions are if the reading 2 hours after shocking was that low with FC will it get better after a few hours or not? Does having trees cause it to lose FC from buds falling in the pool? He vacuums it pretty much daily. I have read on other sites about a chlorine block and to slam with a non-chlorine shock? Is that possible we have this? I have read the ABCs of pools and understand FC, CC and TC. If my husband just shocked pool today and FC level is too low tomorrow, as well as CC too high what should we do? He has the hth test kit and he just purchased a Taylor K-2006 complete FAS-DPD chlorine test kit.

If anyone can offer some advise I would really appreciate it.

Karen
 

Brett S

Well-known member
Mar 15, 2019
704
Orlando
If you are trying to maintain your pool at 3ppm of FC that is probably part of the problem. It’s not unusual for a pool to consume 3ppm of chlorine in a day, especially if the pool gets a lot of sun, the stabilizer level is low, and/or there is an algae bloom.

The first thing you need to do is to read the ABC’s of water chemistry here and get your own test kit so you aren’t relying on the pool store’s testing. We have discovered that pool store testing can be wildly inaccrate and that only makes your pool that much more difficult to maintain.

Once you have an understanding of how the water chemestry works and you have your own test kit, then you need to figure out what your CYA level is and start a SLAM to get rid of your algae bloom (that’s what’s causing your water to be cloudy). After the SLAM is complete you can move forward knowing exactly where you need to maintain the FC level based on your CYA level.
 
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kmarcel

Member
Jun 20, 2017
10
Syracuse, NY
We did a SLAM (we used Bio Guard Burn out # 73) yesterday and as I said in my first post that after the SLAM the FC was only about 1ppm. This morning my husband added more chlorine so this morning the FC is about 7ppm and the CC is less than 1ppm, PH 7.4.
How do you know when the SLAM is complete, after you do it or a certain amount of hours later?
We have our own test kits, as I described in my original post and have read and understand the ABC's. Now I'm just trying to fix it. Water is very cloudy this morning. Also added an algaecide yesterday as well.

Karen
 

Mdragger88

Bronze Supporter
Jun 1, 2018
1,199
Hernando, Ms

You may have brought your pool to shock level but you must maintain that level for your cya FC/CYA Chartuntil u meet all 3 end of slam criteria -
1- crystal clear water
2- .5 cc or less
3- pass Overnight Chlorine Loss Test

Algecides don’t kill algae they can only somewhat prevent it from growing. Lots of them contain copper as well which can turn blonde hair & fingernails green.
 
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kmarcel

Member
Jun 20, 2017
10
Syracuse, NY
Okay I watched the video and read the ABCs and feel I understand, just unsure of how to fix the problem.

This morning, as I stated, the CC was 1PPM (too high I know) and the FC is now at 7. The CYA is 30-40. Water extremely cloudy. The shock that we have been using is a powder Burnout 73. The video says to use liquid. My question is how often should we check the CYA? Also, what level should we keep the FC at? He will test the FC & CC again this evening and tomorrow am early for the overnight test. But I'm still confused about continuing the slamming process until you achieve clear water, less than .5 CC and pass the overnight FC test, especially given the high FC and CYA level right now.

I have watched and read everything on this site. Do we just keep slamming when the FC is as high as it is, but the CC is also higher than it should be and the water is very cloudy? At what point do we slam again, when the FC drops or when the CYA drops to a certain level? Also, should we switch to liquid shock instead of the powder burnout 73? We have the test kit that is recommended in your video and test several times a week. However, when there is an issue he will take a sample to the pool store and they tell him how much to add or what. So if we switch to the liquid shock can you recommend how much we should use?

Karen
 

Mdragger88

Bronze Supporter
Jun 1, 2018
1,199
Hernando, Ms
Use the SLAM Process with liquid chlorine- no more burn out!
1st : lower ph to 7.2
Then:
TEST & add liquid chlorine multiple times daily but no more than once per hour to maintain shock
target fc of 16 as your cya is 40 - you always round up for cya test if in between so you can be assured u use enough chlorine
Only fc & cc are tested during SLAM Process
You are done when:

When all three are true, you are done SLAMing and can allow the FC to drift down to normal levels.

You will get poor results mixing our suggestions w/ pool store advice.
 
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Mdragger88

Bronze Supporter
Jun 1, 2018
1,199
Hernando, Ms
Cloudy water means algae is eating your fc. It will get a second wind every time you go below shock level (this is why the maintain part is so important)
The end of slam criteria is there to be sure algae is eradicated otherwise it will just return.
It is safe to swim up to Slam level (16) for your cya.
5- 7 ppm fc is only maintenance level for your cya - it is far from high chlorine levels
3ppm is bare minimum & should not be used as a target lest things will grow ?

Dumping powder shock in your pool has the potential to damage your liner while pouring liquid chlorine in front of a return & brushing the area will not .
not to mention you’re adding calcium with every use of the burn out .
Also use the logs in PoolMath app
It helps us see where u are with levels etc.
If you tap my pic you can click on my poolmath logs & you will see i am slamming as well - it may help u understand the process
 

kmarcel

Member
Jun 20, 2017
10
Syracuse, NY
Mdragger88, just so I understand you are saying to get our FC up to 16 based on what our CYA level is at? We have a small pool, about 5,000 gallons. Can you tell me how much liquid chlorine we should add to start with? After we add that amount we keep adding until it's up to 16ppm? We have never had our chlorine that high so this is very foreign to us. Clearly that's our problem. So during this process we only check FC and CC, do not worry about the CYA?
Also, can you tell me how much product we would need to add to lower to 7.2? And also is that really necessary since it's at 7.4 or 7.5 right now?

Also during this process which sounds like it may take a few days, I assume no one can swim? Our grandchildren are here from out of town for the next two weeks and I really want them to be able to swim.
 
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aeh0603

Well-known member
Apr 6, 2016
353
San Diego, CA
We recommend using PoolMath to calculate how much of a given chemical is needed. If you are on a computer, there is a link to the PoolMath webpage at the bottom of the page. If you are on a mobile device, there is also an app available.

How much chlorine and acid to add will depend on what concentration/strength of the chemical you have. All that information as well as your pool size can be entered into PoolMath and it will do the math for you so you know how much to add.

Please do not add chlorine and acid at the same time. Allow at least 30 minutes between those two chemicals for safety to ensure the first is fully mixed in before adding the second.

It is safe to swim if FC is in between minimum and SLAM level for your CYA per the FC/CYA chart AND you can see the entire bottom of the pool.

Do you have one of the recommended test kits to test the water yourself?
 
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kmarcel

Member
Jun 20, 2017
10
Syracuse, NY
I went to the pool store yesterday to get the liquid chlorine and they did a water test as well. Yes we do have the test kit that is recommended on this site. He said that we have a chlorine lock, which I had read about and suspected as well. He had us do a non-chlorine shock. That was done yesterday early afternoon. Today the water is still cloudy, although a bit improved, and our numbers are as follows:
FC 4 -5
CC 2
PH 7.1
TA 120
CYA 50

I would assume that we should proceed with liquid chlorine to see if we can get that CC down?

Karen
 

Brett S

Well-known member
Mar 15, 2019
704
Orlando
I went to the pool store yesterday to get the liquid chlorine and they did a water test as well. Yes we do have the test kit that is recommended on this site. He said that we have a chlorine lock, which I had read about and suspected as well. He had us do a non-chlorine shock. That was done yesterday early afternoon. Today the water is still cloudy, although a bit improved, and our numbers are as follows:
FC 4 -5
CC 2
PH 7.1
TA 120
CYA 50

I would assume that we should proceed with liquid chlorine to see if we can get that CC down?

Karen
The first thing that you need to do is choose one method to manage your pool and stick by it. If you want to go with the trouble free pool method, that’s great, we can definitely help you with that. If you want to go to your pool store and get your water tested there and follow their advice that’s great too. But if you take some advice from trouble free pool and some advice from your pool store and just do half and half it’s not going to work at all. It’s going to be very frustrating to you and it’s just going to cause you to waste money.

We tend to be pretty strict in our advice and with our method because we have demonstrated over and over again that it works. As we said above, what we would recommend doing is a SLAM (which uses liquid chlorine, not a non chlorine shock) and using your own test kit, rather than letting your pool store test your water because we have seen wildly inaccurate results from pool store water tests. It’s kind of counter intuitive, but by doing your own tests you will have more accurate results and be much better able to manage your water.

A while ago another member posted tongue in cheek that we are almost like a cult... that we have our method and you need to follow it in order to join our club. That’s not really true, but we can tell you that sort of following our method and sort of following your pool store’s advice will only lead to further frustration. If you want to go to your pool store and follow their advice, we won’t kick you out of the club or anything, but you need to pick one method and go all in.

If you choose the trouble free pool method and need to get liquid chlorine from your pool store just stick your fingers in your ears and say “la la la, I can’t hear you” the whole time you’re in the store;)
 
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splashpad

Bronze Supporter
Aug 2, 2017
2,708
SE Kansas!
... by doing your own tests you will have more accurate results and be much better able to manage your water...
By only using your own testing and test results, it eliminates one variable, the tester! :)

I went to the pool store yesterday to get the liquid chlorine
The Pool Chlorine or Liquid Pool Shock (Sodium Hypochlorite 10% or 12%) can be purchased at hardware stores or even Walmart :) Likely for a fraction of the cost at the pool supply store(s)
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,547
Prosper, TX (DFW)
As others have said, stop going to the pool store. Their tests are unreliable and they always get your to buy unnecessary products, just like the non-chlorine shock for the "chlorine lock" which you dont have.

Also, are those most recent tests your own test results, including the CYA of 50? If so, then your new SLAM target is 20.
 

carnivalday

Gold Supporter
Bronze Supporter
Oct 25, 2017
581
Ocala, FL
@kmarcel You've been going to the pool store and doing what they tell you to do, and you have a cloudy pool. If you continue to do what they tell you to do, you will continue with your problems. The TFP way is very specific, but it works. And ends up being way cheaper than going to the pool store every week for chemicals that you dont even know what they are doing. So its up to you what you want to do, but Id recommend giving the TFP way a chance to clear up your pool. What have you got to lose? (other than a cloudy, hard to maintain pool).
 

kmarcel

Member
Jun 20, 2017
10
Syracuse, NY
I agree that the pool store is adding to this problem that is why I've been reading this site and trying to understand so I can get my husband to stop going to the pool store. But please understand that there is a learning curve for us on this. We now have purchased a gallon of liquid shock which we will do tonight. Our pool is small, approximately 4500 gallons. I have looked at the chart, but do not understand what is meant by a SLAM target of 20. Can someone explain that?
 
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splashpad

Bronze Supporter
Aug 2, 2017
2,708
SE Kansas!
You got this! Everyone started somewhere, no worries! Once you've seen this process work, you'll hopefully feel just as strongly! :D
I agree that the pool store is adding to this problem that is why I've been reading this site and trying to understand so I can get my husband to stop going to the pool store. But please understand that there is a learning curve for us on this. We now have purchased a gallon of liquid shock which we will do tonight. Our pool is small, approximately 4500 gallons. I have looked at the chart, but do not understand what is meant by a SLAM target of 20. Can someone explain that?
If your pool is 10' x 20' oval/rectangle, is it only 4' deep?
 

carnivalday

Gold Supporter
Bronze Supporter
Oct 25, 2017
581
Ocala, FL
The SLAM target of 20 is what you need to get your FC level up to, with a CYA of 50. You will have to check frequently so that it doesnt go below 20...keeping it a bit higher is okay. You will be needing a lot more chlorine, so Id start to look for a good cheap supply.....Walmart, Lowes, Home Depot are popular options.