odor causing swimmers to cough

[HoosierStacey]

Hi, I have an 18,900 gallon in-ground fiberglass pool. This will only be our 3rd full summer since having the pool installed. This season we have noticed a smell any time the water is disturbed (swimmers, crown jets running). Whatever the smell is causes occupants to cough. We have always used Bioguard chemicals. No one at our local pool store, or the local Bioguard rep, has any idea what could be causing our issue.

We changed the sand in our filter 3 days ago hoping that would resolve the problem, which it hasn't. We also triple shocked with lithium hypochlorite - chlorine levels are still high from that but no change in the irritation.

Here are the results of yesterday's water test :

saturation index : normal
pH : 7.5
total alkalinity : 106 (we added bal pak 100)
total hardness : 465 - Indiana hard water!
TDS : 2750
Free Chlorine : 11.8
Total Chlorine : 11.8
CYA : 112
Optimizer Plus : 37

Have you ever heard of this issue? Any ideas how we can fix it?

I appreciate any input you may have.

[Denniswiseman]

Generally speaking when you get smells with pool water it's combined chlorine but your results don't show any CC (TC-FC)
How do you test your water, with a FAS/DPD kit. Ideally you should have your own test kit as pool stores and strips are widely inaccurate
You don't need special over priced chemicals to sanitise and balance your water
Liquid chlorine (sodium hypochlorite or plain bleach)
Muriatic acid (hydrochloric acid) to lower pH and TA
Bicarbonate of soda to raise TA
Aeration will raise pH only
Soda ash will raise pH and TA

[HoosierStacey]

Thank you for the information. I do have a test kit that I use to compare the results to the pool store’s test.

My pool is crystal clear so I can’t think of anything that would be causing this issue. Is it possible there’s something in the plumbing lines causing the odor? If so, do you have a recommendation as to how I can flush it out?

[Teapot]

Could the smell be from the decomposing of your wallet from buying expensive lithium hypochlorite and the other overpriced chems you don't need?
You have UV and an ozonator and you still need the rest of the junk?
Your CYA is high meaning your shock level would need to be 44ppm so I would empty and re fill about half the water. I would also get the ozonator checked and the ozone around the water line, Ozone is very dangerous to breathe and can quickly damage the airways and kill if there is an issue with too much or leaks.
I would get a camera inside the lines to inspect for biofilm as well, chlorine dioxide can remove biofilm but mechanical removal may also be required if there is much.

Do yourself a big favour and stop using these not needed overpriced products and get back to pure water, you didn't need to add alk+ (balpak 100) as your pool is fibreglass, all you have done now is to make the pH rise faster meaning more ph- will be needed to bring it back down again, great if you own a pool shop!

How did the CYA stabiliser get so high if you use lithium (unstabilised chlorine)??