No Free Cholrine

[JNC]

I have a 16500 gal above ground pool. I use a cartridge filter with 1.5 hp. I replaced about a quarter to one third of the water volume when I opened up the pool. I tested the water and took a sample to my local pool store expert. PH, Alkalinity, CYA all within acceptable limits. I put in about 3 lbs of shock (Calcium hypochlorite) followed much later the same day by about 2.5 lbs of chlorine (sodium-dichloro-s-triazinetrione dihydra). After a day the pool registered free chlorine at about 3 ppm. I put in another 6 ounces of chlorine as maintenance. It was raining. Today less than 24 hours later, it is sunny and there is no trace of Free Chlorine. I have never gone through chlorine this fast. Please help me understand what is going on and how I can fix it. Thanks.

Thanks for you reply. I will be purchasing a better test kit and getting back to the community with better results. I just returned from Leslies. The tech there told me told me that the FC = 0, he did not provide a number for CC. PH = 7.4, TA = 100, CYA he did measure directly but in a previous test a few days ago I was told it was 30, CH was not measured. Strangely he used an Aquacheck strip to check the chemicals instead of the usually liquid agents. I had an algae bloom today in several spot around the bottom of the pool wall. I am in the process of treating same with shock.

 

[dschribs]

Re: NoFree Cholrine

I'm a new pool owner - this year - but i found out pretty fast the key to proper water balance and determining what is going on with your pool is getting a good test kit and testing the water yourself. You'll find the pros on here will need water test results before they can even begin to help you.

Forget the pool store unless you need a leaf basket or inflatable float.

 

[msgtdan]

Welcome to TFP

Sounds like you may need to go through the shock process, for that we'll need good numbers preferably from either the TF-100 or the K-2006. You can start with Pool School in the upper right corner. Shocking is a process that involves getting chlorine up to shock level and keeping it there until you've passed 3 criteria. Clear water, .5 cc or less and losing less than 1 ppm FC overnight.

 

[jblizzle]

Welcome to TFP!!!

As the previous responders have stated, we need better test results that "within acceptable limits" because the pool store limits and out recommended ranges are vastly different.

Look into ordering one of the Recommended Test Kits and then you will need to follow the Shocking Your Pool PROCESS.

Really the key to know the next step is the CYA number ... which also happens to be the test that the pool stores are notoriously the worst at getting right ... thus getting your own test kit is the key.

 

[JNC]

Forgive my lack of knowledge but I have a question regarding the Shock Process. I may not be using the correct terminology but to try to get the FC correct I am dealing with 2 chemicals. One is what I call Shock (calcium hypochlorite 73% Power Powder Plus) and the other is what I call regular chlorine (sodium-dichloro-s-triazinetrione dihydra 99% also known as Chlor Brite) which I purchased at Leslies. In step 4 it says add enough chlorine to bring FC up to shock level (or a little higher). I am correct in assuming that either the K2006 or F-100 tests kits measure FC and Shock independently? And that I am to add some quantity of chlorine until the numbers for Shock and Chlorine are equal ? If so how much chlorine do I add?

Also I am not quite sure how to use the the chlorine/cya chart. What do the numbers mean. I imagine we begin by measuring CYA. The other numbers I assume represent ppm of FC. If so, if the measurement for FC is lower than what is in the chart for a given CYA, what do I do to adjust the levels?

Thank you again.

 

[jblizzle]

I think you would best off taking a breather and reading some more in Pool School (button at the top right of the page).
Start here: pool-school/pool_water_chemistry

We do not call anything "shock" because it means too many different things to different people.

You should be using liquid chlorine (bleach) to be adding your chlorine as it does not have the side effects of the solid forms: pool-school/types_chlorine_pool

The FAS-DPD test will measure FC and CC independently in ppm. The values in the CYA/FC chart are in ppm.

 

[Speedo]

I am dealing with 2 chemicals. One is what I call Shock (calcium hypochlorite 73% Power Powder Plus) and the other is what I call regular chlorine (sodium-dichloro-s-triazinetrione dihydra 99% also known as Chlor Brite) which I purchased at Leslies.

You're dealing with two different products, one contains calcium and chlorine. The other contains chlorine and cyanuric acid. As Jason said, use liquid chlorine because it doesn't contain any unnecessary chemicals. You're far better off adding everything individually. (when it's actually needed)