96 oz LC does not move FC

[BoHpool]

Walmart is out of Pool Essentials chlorinating liquid so I went to Home Depot and bought it there. It has a date code of 205, 35 days old. It is stored in the garden center, outside in deep south Texas. My FC was 2 after a hard rain today so I added 96 oz of the Home Depot LC around 5 PM. I tested FC at 9:15 and FC has not raised at all. CYA 45, TA 110, CH 330, pH 7.4. I think the LC from Home Depot is not good and I plan to take it back for a refund. Am I off base or is my thinking OK?

 

[Burke_B]

You have 2 pools listed. Did you add that to your larger one? If so, according to pool math, that should have raised it by 2. You should be shooting for 6-8 (Chlorine / CYA Chart) for a CYA of 50 (round up to the next 10). Not sure what you were previously keeping it at because I can't see your logs for some reason. From what I have read here, the rain shouldn't really lower your FC that much. If you have been keeping it on the low side, and you waited over 4 hours to test it again, I would suspect you have some organics that are using it up and you likely lost some to UV from the time you put it in and the time you tested. I would Add enough to get to the high end of the range for a CYA of 50 (before going to bed tonight), wait 30 minutes, and then test it and see what you get. Then, test it again before the sun hits it in the morning and see if you lost any (OCLT: Perform the Overnight FC Loss Test (OCLT)). If you fail the OCLT, you need to SLAM: SLAM - Shock Level and Maintain

 

[BoHpool]

I have not been able to get Pool Math to work for me. Yes, it is the larger of the 2 pools. It was overcast from when I added the LC until I checked the FC, so sunlight should not be a problem. The pool was at about an FC of 2 all day, I started an LC feeder two days ago and it has been keeping the FC pretty steady. I have done the OCLT several times and don't think organics are the problem. After the rain, the pool surface is covered with may-flies so I shocked the pool and will start over tomorrow.

 

[YippeeSkippy]

If you're on a computer here is the old classic web version of PoolMath-

PoolMath

Discover the calculator behind the perfect pool, PoolMath. Dealing with pools has allowed TFP to become the original authors of the best calculator on the net.

www.troublefreepool.com

Make sure you first enter in the pools volume, then go to the bottom and select "type of pool" "how you chlorinate" and "Troublefreepools"
For Liquid Chlorine use the term "bleach".

Maddie

 

[YippeeSkippy]

Don't add anything else to your pool but Liquid Chlorine. For a pool that large I imagine you'll be adding more than a gallon early on if your FC is that low.
Consider your CYA to be 50, as their are no "half ways'" (its a logarithmic scale, not a linear one)
A FC of 2ppm is just an invitation to algae.
Remember to follow the CYA/FC chart --> FC/CYA Levels

 

[ajw22]

Test your FC, then add your LC, then test your FC 30 minutes after adding the LC to measure the effect of adding the LC.