Chlorine adding calc troubles with Taylor Test Kit K-2006

[OctopusSquid]

Hey team!

My pool's free chlorine level is 3.5 and I'd like it up to 5. Before I got rid of my $$$ pool company, they were adding on average 2 gallons weekly. However, when I used the chart at the back of the Taylor test kit (and confirmed with the Pool Calculator) it only suggests adding about 1/4 gallon of chlorine. Have any of you come across discrepancies like this? My gut says to continue with the 2 gallons but I want to better understand this calculation. Thanks!

 

[duraleigh]

Welcome to the forum!

Chlorine is a consumable item so the demand will vary depending on how much is currently in your pool. You should be testing to measure the existing amount of FC and then calculating and adding enough to get to 5 ppm. Rely on the calculator to tell you how much.

Your post is a bit confusing as if you want to simply dose an amount regardless of the calculator. Don't do that.

 

[ajw22]

Welcome to TFP.

Also chlorine consumption declines in the winter with colder water temperatures and lower sun angle. So the amount of chlorine you are adding will vary during the years.

Are you using liquid chlorine? What % chlorine?

I suggest you read ABCs of Pool Water Chemistry

 

[OctopusSquid]

Welcome to the forum!

Chlorine is a consumable item so the demand will vary depending on how much is currently in your pool. You should be testing to measure the existing amount of FC and then calculating and adding enough to get to 5 ppm. Rely on the calculator to tell you how much.

Your post is a bit confusing as if you want to simply dose an amount regardless of the calculator. Don't do that.

Thank you for your response! I calculator and the Taylor test kit suggest about 1/4 gallon of the 12.5% liquid chlorine. I guess I just wanted to make sure that that was correct as that seems like a very low number especially considering the previous pool service had been putting in two gallons weekly which has been maintaining my chlorine levels from 3 to 5 consistently. I found it kind of odd that suddenly when I start testing myself the amount required dropped significantly.

 

[OctopusSquid]

Welcome to TFP.

Also chlorine consumption declines in the winter with colder water temperatures and lower sun angle. So the amount of chlorine you are adding will vary during the years.

Are you using liquid chlorine? What % chlorine?

I suggest you read ABCs of Pool Water Chemistry

Thanks for responding! I am using liquid chlorine 12.5%. the calculations on the calculator and the Taylor test kit booklet chart were based on this percentage as well. Thank you for clarifying, I should have mentioned that period I guess I am just surprised that the requested amount dropped from 2 gallons every week with the pool company which maintain my chlorine level from 3 to 5 and now when I am testing myself the requirements have dropped significantly. I guess I just wanted some clarification if that made any sense or if I am missing something.

 

[mknauss]

To raise your FC from 3.5 to 5 ppm will take 32 ounces of 10% liquid chlorine.
Remember your pool service only would be there once a week. So they raised the FC far higher so that after a week hopefully there was still some chlorine in the water.

What is your CYA?

 

[ralphsyv]

I had the same situation. The pool service was adding 2-1/2 gallons to 5 gallons of liquid chlorine all at once every week. They came in the middle of the day, so sunlight burned off a lot of the chlorine. If you are doing it yourself, you are probably going to add chlorine in smaller amounts. It depends on your cyanuric acid (CYA) level.

 

[OctopusSquid]

To raise your FC from 3.5 to 5 ppm will take 32 ounces of 10% liquid chlorine.
Remember your pool service only would be there once a week. So they raised the FC far higher so that after a week hopefully there was still some chlorine in the water.

What is your CYA?

Ok, perfect. Thank you for the confirmation. I think I was thrown off by how different my calculation was. My CYA is 60 (down from 150 when we first moved into the home a few months ago when the previous owner was using tabs).

 

[mgtfp]

Remember your pool service only would be there once a week. So they raised the FC far higher so that after a week hopefully there was still some chlorine in the water.

I think that really is the key. Adding enough to survive one week is the only way a pool service can manage a pool, meaning that chlorine will likely go from very high to very low over the course of that week.

Don't try to copy that, it is much better to test and adjust more often. If adding chlorine daily or at least a couple of times a week is too much of a chore, than a Salt Water Chlorine Generator is a good alternative (the best alternative, actually...).

But during winter you might actually be fine with weekly maintenance, once you've understood your pools needs.

 

[OctopusSquid]

Perfect. Thank you all very much. This has been very informative and validating! Really appreciate your insight.