Combined Chloramines

[fkeeley]

Hello all,

We have an 18x33 oval 4 ft deep pool.

Opened it last week. I haven't been able to hold chlorine in it this year, this has never been a problem. I figured shocking was the answer.

Anyhow with no success on my own I took my sample to the pool store.

(My readings were pH of 7.5, alk 160, FC 1, CC 7 and 0 cy acid)
Pool store had my pH at 7.4, alk 140, FC ) and CC 6.8 and 0 "stabilizer". I asked about the stabilizer and they said a chlorine demand can mask the stabilizer so worry about dealing with the CC first.

So 38 lbs of shock later (Burnout 73) my FC is still reading 0, but according to my test kit my CC are down to .5. Despite the burnout saying that it would increase my pH, my pH level was reading 6.8. I added 3lbs of pH increaser and turned my chlorinator up to 7 and called it a night since its getting dark.

So I assume the answer is more shock (assuming my pH is normal by morning) and potentially stabilizer?

Any thoughts?

We had a new liner placed 2 years ago, no issues last year. We did essentially have to replant our entire back yard last year. So I'm not sure if that is the culprit of my problem this year.

 

[tim5055]

Welcome to TFP!!

Well, lets go thru this one item at a time.

(My readings were pH of 7.5, alk 160, FC 1, CC 7 and 0 cy acid)

I trust your testing more than I do theirs. Not much credence is given to pool store testing around here. While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing. Plus, the results of their "testing" is used to convince you that you need to buy things. Why do you think that testing is free?

So, this begs the question - what test kit are you using?

I asked about the stabilizer and they said a chlorine demand can mask the stabilizer so worry about dealing with the CC first.

Their advice is as good as their testing. Chlorine demand has noting to do with CYA testing.

I added 3lbs of pH increaser and turned my chlorinator up to 7 and called it a night since its getting dark.

pH increaser, From the pool store? The best pH increaser going is Borax from the laundry isle at the grocery store. You don't get teh fancy package, but then you spend 2/3 less then the fancy pH Increaser package.
What kind of "chlorinator"?

So I assume the answer is more shock (assuming my pH is normal by morning) and potentially stabilizer?

Depends on if you like the pool store system, or if you want to follow a bunch of renegades on teh internet. We never "shock" our pools, but I'll get to that later.

Any thoughts?

Several---

First, that Burnout 73 is Calcium Hypochlorite. Another fancy package at an inflated price. You don;t show any test results for Calcium Hardness, CH and that is where Calcium Hypochlorite shows up.

So, We base our pool care system on accurate testing and only adding what the pool needs, when it needs it. To do that you need your own accurate test kit. Whe I see the answer to what kit you are using we can advise if it is suitable to use to follow our methods. To effectively practice the TFPC methods, the FAS/DPD chlorine test is essential as it can measure up to 50ppm of FC with an accuracy of .2 when needed, very few kits have this test.

To clear you pool we follow a procedure called a SLAM Process. Instead of a one time "shock" of the pool, we bring it up to shock level (the SL) and maintain it (the AM) at shock level constantly until we can prove through testing (remember that FAS/DPD test I talked about) that all of the organics in the pool have been eliminated.

Oh, I forgot - your landscaping probably had noting to do with this unless they threw all the old plants in the pool.

 

[fkeeley]

Im using the TF 100 test kit.

Tested the calcium hardness last week when I opened, did not retest today, was pretty focused on the CC. It was WNL on opening. I did use pH increaser I ordered from In the Swim and had left from last year.

In line chlorinator with the "pucks". Came with pool when we bought the house, we left it as part of the system. Usually just throw 2 pucks in a week and keep it set at 2.

This is by far the worst this pool has ever opened for me in the 9 years we've owned the house.

 

[Richard320]

Most likely, you were one of those lucky few who had all his CYA break down into ammonia over the winter.

It takes about 10X FC to neutralize ammonia. The intermediate product is CC. This would easily account for 1) No CYA; 2) High CC; nearly unquenchable thirst for chlorine.

A secondary confirmation would be that you could really smell the bleach smell when you dose the pool -- that locker-room scent.

Once it's gone, it;s gone, and you can add a little CYA to protect the chlorine from the sun and go on about the business of killing the algae now that the ammonia is goine

 

[fkeeley]

Richard, most definitely smelled the "chlorine" smell when adding all the shock today. In addition to it clouding and foaming like nothing I've ever seen. It's since cleared up, however, still have 0 FC and .5 CC per my test kit.

 

[tim5055]

It's time to SLAM Process the pool, but if you did in fact have an ammonia conversion, you need to eliminate the ammonia first.

First, do not add any CYA - it could also get converted and add more ammonia. (remember the tabs have CYA, so turn off that tab feeder)

So, add the amount of liquid chlorine you need to get to 10ppm with the pump running. Wait 30 minutes and retest.

You will have to do this over and over until the FC begins to hold above 5ppm. At that point we can assume the ammonia has been eliminated.

 

[fkeeley]

I read the SLAM feed but I’m not sure how much liquid chlorine (i assume you mean bleach here) I’m going to need to add
initially / and have on hand, and it what % I need to buy.
I will recheck in the morning & post but like I said last check FC was 0, CC .5 cya 0 & pH was 6.8 (which I added increaser & based on your slam feed may have been a mistake since that said pH is unreliable during a slam - I did add 38 lbs of shock)

sorry to be a pain

 

[fkeeley]

Also I went down and pulled the tabs out of the inline chlorinator

 

[tim5055]

I read the SLAM feed but I’m not sure how much liquid chlorine (i assume you mean bleach here) I’m going to need to add
initially / and have on hand, and it what % I need to buy.
I will recheck in the morning & post but like I said last check FC was 0, CC .5 cya 0 & pH was 6.8 (which I added increaser & based on your slam feed may have been a mistake since that said pH is unreliable during a slam - I did add 38 lbs of shock)

sorry to be a pain

Nope, not a pain!

First, don't worry about the pH increaser addition. We only advice not to adjust pH during a SLAM Process because the pH test is inaccurate when FC is above 10. You are well below 10, so it's fine.

Now, how much liquid do you need?

I used Pool Math using a volume of 15,700 gallons, going form "0" FC to 10 FC you would need one of the following (in ounces)
6% 326 (2.7 bottle of standard bleach)
8.25% 232 (2 bottles of "concentrated" bleach)
10% 201 (1.5 bottles of 10% chlorinating liquid "shock")
12.5% 161 (1.25 bottles of 12.5% chlorinating liquid "shock")

So depending on which type you find the least expensive multiply the number of bottle to do it once by at least 3, because I'm sure you will be doing it at least that many times. Overbuying will not be a problem because you will need more liquid for the SLAM Process, so stock up.

 

[fkeeley]

Am numbers
pH 6.8
CH 475
FC 0
CC 0.5 (changed to almost undetectable shade of pink)
CYA 0
alk 140

Threw another 3 lbs of ph increase in
before I left house

 

[splashpad]

Welcome to TFP!

Can you add these details to your signature for us?

Am numbers
pH 6.8
CH 475
FC 0
CC 0.5 (changed to almost undetectable shade of pink)
CYA 0
alk 140

Threw another 3 lbs of ph increase in
before I left house

Are you picking up liquid chlorine today? I don't think you're pool needed PH increase.

If you can find an elbow that fits in your return (see below) you can use your pump run time to aerate and raise PH with your high TA value

 

[fkeeley]

I will add the details to my signature today

planning on running to Lowe’s this morning

assume I should be picking up some cya to add after I’m able to hold my fc levels ?

 

[Richard320]

I will add the details to my signature today

planning on running to Lowe’s this morning

assume I should be picking up some cya to add after I’m able to hold my fc levels ?

Yes. If water is green, only add enough to get to 30 initially. If clear, then go for your target.

 

[tim5055]

assume I should be picking up some cya to add after I’m able to hold my fc levels ?

It wouldn't be bad to have it on hand.

 

[fkeeley]

So to verify I’m adding 1.5 bottles of liquid shock (10%) every 1/2 hour until I hold my FC at 5, for how long?

 

[mknauss]

So to verify I’m adding 1.5 bottles of liquid shock (10%) every 1/2 hour until I hold my FC at 5, for how long?

You raise your FC to 10ppm, circulate for 15-30 minutes, test FC, if 5 or below, add chlorine to get back to 10 ppm, repeat until your FC is above 5. Then adjust pH and go to SLAM. Add CYA if necessary.

 

[tim5055]

So to verify I’m adding 1.5 bottles of liquid shock (10%) every 1/2 hour until I hold my FC at 5, for how long?

Close -

Add 1.5 bottle the first time, which should bring you to 10.

After 30 minutes test the water. If FC is 3 at that time you would only need to add 141oz as you already have FC 3 in the water, you just need to make it back up to 10.

Use PoolMath to make the calculations for you. Put 15,700 in the size box at teh toip and the very first section is the FC calculator. Put your test results in the first box (Now) and 10 in the second box (Target) hit tab and to the right it will tell you how much to add of what to get to your target. The first time you use it you will have to tel lit that you are using 10% and the bottle size.

After 30 minutes test again. if this time your FC is 4 then you only need to add 120oz.

You will continue this process until you test it and you have 5. A winner. Time to start theSLAM Process

 

[splashpad]

So to verify I’m adding 1.5 bottles of liquid shock (10%) every 1/2 hour until I hold my FC at 5, for how long?

Use PoolMath to figure out how much 10% liquid chlorine to add (Chlorine Now/_?_ Goal/_5_) for your pool size at your CYA level of 30 ([FC/CYA][/FC/CYA])
... yes, check FC level and (if below target) add chlorine ~30min (to hold your Goal(target) FC level)

 

[fkeeley]

So to verify I’m adding 1.5 bottles of liquid shock (10%) every 1/2 hour until I hold my FC at 5, for how long?

 

[tim5055]

So to verify I’m adding 1.5 bottles of liquid shock (10%) every 1/2 hour until I hold my FC at 5, for how long?

Close -

Add 1.5 bottle the first time, which should bring you to 10.

After 30 minutes test the water. If FC is 3 at that time you would only need to add 141oz as you already have FC 3 in the water, you just need to make it back up to 10.

Use PoolMath to make the calculations for you. Put 15,700 in the size box at teh toip and the very first section is the FC calculator. Put your test results in the first box (Now) and 10 in the second box (Target) hit tab and to the right it will tell you how much to add of what to get to your target. The first time you use it you will have to tel lit that you are using 10% and the bottle size.

After 30 minutes test again. if this time your FC is 4 then you only need to add 120oz.

You will continue this process until you test it and you have 5. A winner. Time to start theSLAM Process