New owner trying to balance pool

[Chris2109]

Hi everyone,

I recently purchased a house with an above ground pool (~13k gallons). I'm trying to balance using liquid chlorine 10% and muriatic acid using the K2006 test kit. All I know about pool care is from looking through forums last night. below are my results.

After opening: BioGuard water analysis
FC- 0
CC-3.8
PH- 8.4
TA-200
TH- 155
CYA-130

I added 4 gallons liquid chlorine and 1 gallon muriatic acid (currently aerating).

Next day results: K2006
FC-5
CC-4
PH-7.2
TA-220?
CYA- ~120 (hard to tell but close to the 100 line)

I really don't want to drain the pool to fix the CYA. Can I operate it at this level? I plan to add 7 gallons liquid chlorine tonight to "shock". Am I on the right track?

Any advice is appreciated!

 

[mknauss]

Welcome to the forum!
Can you fill our your Signature to record the pool type, volume, equipment, etc? Helps us help you.
You really do need to lower your CYA. Do the CYA dilution test described in Step 8 of CYA test directions.
The CC of 4 says your water has a problem. You need to SLAM Process. But you cannot do so until you lower your CYA to 50 ppm or so.
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

 

[Chris2109]

Welcome to the forum!
Can you fill our your Signature to record the pool type, volume, equipment, etc? Helps us help you.
You really do need to lower your CYA. Do the CYA dilution test described in Step 8 of CYA test directions.
The CC of 4 says your water has a problem. You need to SLAM Process. But you cannot do so until you lower your CYA to 50 ppm or so.
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

Thank you for the quick reply. I just updated my signature block. I did the diluted CYA test and got 120. How much of the pool would you recommend draining? Everything I have read has said high CYA like that is bad but the pool store said it was fine between 50 and 200?

 

[mknauss]

You need to exchange at least 60% of your pool volume. Draining is OK, but do you have a high water table? A pool can pop out of the ground if drained improperly.

Pool store does not follow nor understand the FC/CYA Levels relationship. You will find quickly that TFP is science based, not based on what the chemical companies tell the pool stores.

 

[mknauss]

I just noticed you said "semi" inground pool. So this is a vinyl liner? Please add that to your signature.
With that, you should be able to drain down 18" to 24" each time. It may take 2 or 3 times of drain and refill to lower your CYA.

 

[Chris2109]

I just noticed you said "semi" inground pool. So this is a vinyl liner? Please add that to your signature.
With that, you should be able to drain down 18" to 24" each time. It may take 2 or 3 times of drain and refill to lower your CYA.

Correct, vinyl liner. I will start draining/ replacing water and go from there. Thank you for the help!

 

[Chris2109]

Welcome to the forum!
Can you fill our your Signature to record the pool type, volume, equipment, etc? Helps us help you.
You really do need to lower your CYA. Do the CYA dilution test described in Step 8 of CYA test directions.
The CC of 4 says your water has a problem. You need to SLAM Process. But you cannot do so until you lower your CYA to 50 ppm or so.
I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

So I replaced water and my CYA is now at 70. I have began to SLAM the pool and having issues with the overnight chlorine loss test. Water is clear and CC is 0. I'm losing a lot of chlorine over night, about half of the SLAM target. Does this just mean there is something bad in the water still? Or could something else be going on?

Thank you.

 

[splashpad]

So I replaced water and my CYA is now at 70. I have began to SLAM the pool and having issues with the overnight chlorine loss test. Water is clear and CC is 0. I'm losing a lot of chlorine over night, about half of the SLAM target. Does this just mean there is something bad in the water still? Or could something else be going on?

Thank you.

SLAM Process = Shock Level AND Maintain So you will have to keep raising the FC level until it stops dropping Good job so far!

Can we see a pic of the pool?

 

[justinc]

I'm losing a lot of chlorine over night, about half of the SLAM target. Does this just mean there is something bad in the water still? Or could something else be going on?

Thank you.

If your free chlorine is dropping by more than 1ppm overnight, it means the chlorine is being consumed by something in the water, so yes, something bad is still in there. Keep SLAM-ing!

 

[Richard320]

So I replaced water and my CYA is now at 70. I have began to SLAM the pool and having issues with the overnight chlorine loss test. Water is clear and CC is 0. I'm losing a lot of chlorine over night, about half of the SLAM target. Does this just mean there is something bad in the water still? Or could something else be going on?

Thank you.

Two things consume chlorine: sunlight and organics (algae). You've eliminated sunlight by testing after sunset and before sunrise. So if you're still losing chlorine, it has to be organics.

Common hiding places are behind lights and beneath and inside ladders.
See Think I may have found my FC demand issue? and Problem Found and Ideas needed and Water problems

If you've got plastic wedding cake steps, it's almost a given that there is algae lurking inside.