Sudden excessive chlorine loss!!!

May 29, 2015
47
Cincinnati/ohio
Current readings:
CYA 40
FC 16
CC .5
pH 7.0
TA 90

Pool has been looking great since initial SLAM upon opening. Last month performed AA treatment for iron staining and it has been gorgeous. After ridding the pool of the iron stain I added CYA and currently it is testing at 40 and using about 1/2 gallon of 10% bleach per day. This has been very consistent for at least 2 months. This week the water started turning a turquoise color... (I think possibly due to thinking my CYA to be less than it was). On Wednesday I raised to SLAM level for my CYA and the water was beautiful within 24 hours. Lost 2 ppm throughout the day Thursday. However, overnight Thursday we burned through 4ppm of chlorine. I maintained at SLAM level all day today (Friday). Checked again this evening and had burned through 8ppm in the last 6 hours!!! I actually performed the test again because I could not believe this to be accurate. Why is the chlorine loss progressively increasing?? Shouldn't it be improving? It didn't burn through this much when the water was turning green!!! As a previous owner of an SWG pool I am tiring very quickly of liquid chlorine. Please see disclaimer below...

DISCLAIMER: This is actually my in-laws pool that I am caring for while we temporarily live here. We owned a saltwater pool in our previous home and I will NEVER understand why you would want anything else. In the four years of owning our pool we never once had algae. I only learned the SLAM process after landscapers lost a wheelbarrow full of dirt in our pool. This site has taught me everything I know.
 
If you are confident in the CYA reading, I would keep it at SLAM level until you can pass an OCLT. Something is eating the chlorine up. Maybe start testing and dosing every few hours for a bit just to be sure.

Otherwise, verify your CYA test to be sure you’re actually at a SLAM level.
 
Last edited:
Maybe there’s some algae growing in a ladder/steps/light niche that the chlorine is fighting? Is anyone using the pool?
 
tekgeek I have been SLAMing since Wednesday. That's why I'm confused, FC loss is increasing. I'm confident my CYA is not greater than 40, if anything it's less. I will check back tomorrow after OCLT and let you know what happens. Hopefully we are on the home stretch!
 

Enjoying this content?

Support TFP with a donation.

Give Support
Mother in law added 2 gallons 12.5% chlorine at noon today since we wouldn’t be home until later. Tested when we got home tonight:
FC 11
CYA 30. Hubby was 2nd set of eyes for cya and confirmed 30.

This confirms shock level to be 12. Crazy we are still burning through chlorine this quickly. Water looks great.
 

Attachments

  • D773132D-2855-4407-918D-41846C5630AB.jpeg
    D773132D-2855-4407-918D-41846C5630AB.jpeg
    516.5 KB · Views: 14
Hard to tell from the picture how clear it is.

See head or tails on a quarter on the bottom of the pool?
 
Hello all....Just wanted to give an update and thank you for the moral support throughout my frustration. We passed our OCLT and quarter is clearly "tails" in the deep end! Iron stain is slowly returning so water is not as pretty but i'm not sure i want to address that right now as it is really hot in Cincinnati and I don't want to drop the chlorine. I recall a thread where swampwoman said Metal Magic or Metal Out (I can't remember) does not require the chlorine drop. Is this correct? If so I might try that. Otherwise don't want to spend the money since we are closing next month. which brings another question i'll ask in another thread. Again... not my pool so not my choice to close so early. Anyway.... chlorine consumption seems to be better, still tracking.
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.