New pool low Chlorine

michaelsliz

Active member
Aug 28, 2010
32
Hi

Hope you can help.

Just got my 18,000 gal in ground pool up and running, filled on Friday, the SWG has been running since Saturday morning.

On testing this morning the test strip showed low for Chlorine, so I took it to a local store to have it more accurately tested and the results were as follows

Salt 3,000 (as of yesterday, was low until then)
Chlorine - 0%
CYA 5ppm

the hardness and ALK is off right now but I dont believe that has a great effect on the chlorine.

I have now got the T-15 cell set to 60% and on super chlorinate for 24 hours.

How long does it take for the chlorine to rise? Or should I be shocking the pool manually? Only reason I have not is that I want to make sure the cell is doing its job. The diagnostics indicate it is.

Help for a newbie anyone? :oops:
 

michaelsliz

Active member
Aug 28, 2010
32
it reads between the second colour (still low) and the green ok, so between off yellow and mid green, the test strip goes light green.
 

michaelsliz

Active member
Aug 28, 2010
32
I was told to run it at 50% by the installers, I now have it on 24 hour super chlorinate mode. its a T-15 cell

The instant salt reading at present is 2900 I added more salt about an hour ago.
 

Bama Rambler

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Jun 22, 2009
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You need to raise the FC with chlorine. The SWCG isn't designed to raise the FC from zero. It's designed to keep the FC up under defined conditions once it's there. You're also going to need some CYA (aka, stabilizer or conditioner) in there before the SWCG will keep up with the sun burning off the FC.

You should read the article in pool school on levels for a SWCG. Then get a good test kit.
 

michaelsliz

Active member
Aug 28, 2010
32
Thanks, just read the pool school it was very helpful.

I will go get some pool shock and stabilzer tomorrow. The reason I did not today was becuase the store said if I manually add chlorine how would I know the cell was working? As a newbie this made kinda sense at the time.
 

duraleigh

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Apr 1, 2007
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teapot's response is meant to help you test to see if the SWG is working and is not related to your overall issue.

YOu probably have algae (visible or not) in your pool. The pool store's test results are likely pretty worthless...especially the CYA result.

You do need to shock your pool and you will have to do it manually to be effective (SWG's aren't any good for shocking) but we need to know an accurate CYA result before we can tell you how high to bring your FC. Simply buying pool "shock" (shock is a verb, not a noun) will likely not help you, it's guesswork.

!. Do you have reason to believe CYA has ever been put in your pool?

2. If so, do you know how much?

3. How does your water look?
 

michaelsliz

Active member
Aug 28, 2010
32
Absolutely nothing has been added to the pool other than myself and water :)

its new install and filled on Friday evening, the chlorinator was turned on about 8.30am on saturday.

The water is crystal clear.
 

duraleigh

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Then your first step is to go to Walmart/Lowe's/HD/Pool Store and purchase enough CYA to raise your pool to 60-80ppm. Then your chlorine will not be burned off by the sun on a continual basis and, in fact, you probably do not have algae at all but your SWG cannot possibly keep up without CYA in the pool.

Have you discovered Jason's pool calculator in my sig? It'll tell you how much CYA you need to purchase.

"The ABC's of Pool Water Chemistry" in Pool School will explain in detail the function of CYA and it's relationship to chlorine. Also consult the FC/CYA relationship chart in Pool School.
 

Darkside of the Pool

LifeTime Supporter
Jul 20, 2010
106
Actually, it is more of a cruise control.

T-Cell 15 Refers to an Hayward product: Salt reading's ok.
CYA helps a lot with a SWCG. The less it has to run to give you the same effect, the longer a cell will last. And those cost around 600$ Canadian... so anything that increases life-span is welcome!
 

michaelsliz

Active member
Aug 28, 2010
32
Thanks Jan ;)

So today i filled my boots with chemicals and set about balancing the water. First stop was my local testing station, the readings were as expected 0 chlorine 0 CYA low alk low calc, high pH :oops:

So not to rush things the first was to find out my exact gallons which is 17238 (US)

I was advised to add

8 cups of CYA - now done
2 bags of shock chlorine about 3.5 cups - now done
4 cups muric acid - now done

The ALk and calc I will leave for tomorrow.

The cell is now at 0% until tomorrow as advised in the manual.

I am now going away for 8 days so will not be able to test the results. But I have tested digitally the pH and it is down to 7.01 and on test strip the chlorine reads normal (as expected I guess)
 

dmanb2b

TFP Expert
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Apr 4, 2009
3,734
NY
8 cups of CYA seems pretty low to me for that size pool. Your CYA level for a SWG pool should be between 60-80. The only way you will be able to confirm that is by getting your own test kit. Stop listening to the store and take charge of the pool. PH at 7 is too low...not sure why they had you add muratic acid.

BBB is more about knowing what your current water chemistry is and the effects of certain chemicals on that chistry than it is about Bleach, Borax and Baking Soda. Never put something in your water unless you understand why you are putting it in.

1st step...get a good kit...the Taylor K2006 or TF100.

Welcome to TFP :wave: As you can see, there are plenty of us willing to help, but a full set of test results is what will help us guide you to fine tuning your water. :goodjob:
 

michaelsliz

Active member
Aug 28, 2010
32
Hi

The pH was up at 8.0 as the water was tested by myself this evening when pH falls anyway (my business is marine fish tanks so have some quite tasty pH testers to hand ;) ) so I am sure the pH will be in tolerance by tomorrow morning.

As I am just about to go away, I am kinda reliant on the stores but will get a test kit for sure. The CYA I added will take a while to get into the system so i have no time to test again before Wednesday really.
 

michaelsliz

Active member
Aug 28, 2010
32
My mistake! No I have not added enough CYA yet, i just worked out how much I have added and how much I should have.

I have added 3.75LB of CYA where I should have added 6LB

Will add some more first thing tomorrow.