water is cloudy and zero fc

[ethany]

Sunday I tested my water. I had a fc reading of 2ppm and cya of 50. I have a swg and it was set to the 3rd led light out of 5. I put the swg at max. output and added 3 lbs. of cya.

Today the water looked cloudy with a fc reading of zero. My ph was at 7.3 so i am going to add 4 lbs of borax.

All summer the water has been crystal clear with no fc loss and a cc of zero. Not sure why the swg stopped producing chlorine. We did get a few heavy showers the past couple days.

Any thoughts?

 

[RobbieH]

If you want to add the borax, add the tiniest bit. pH should drift up because of your SWG.

Most likely you are still producing chlorine, but you have organics in the pool. Do you see tiny bubbles coming out the return when the SWG is running? Can you take a sample right at the return and test it for FC?

My guess is you have something growing in the pool, and it's eating the FC faster than your SWG can manufacture it. You need to perform the OCLT in my opinion.
pool-school/overnight_fc_test

 

[jblizzle]

As you have done, you should raise the CYA closer to the 70-80ppm range.

After checking the OCLT (and after you finish shocking if required), you should be maintaining a higher FC level ... minimum is 3-4ppm, so you should try to hold it closer to 5-6ppm.

Actually, you should not add the CYA until you confirm whether you need to go through the shock process or not.

 

[ethany]

Well unfortunely I added the cya on sunday. My fc was at 4-5 all summer. I have not had to shock the pool at all except when I first open pool in may. No heavy bather load either. Just my wife and son. Do u think I should shock,I guess i should use 50 as my cya.

 

[jblizzle]

Do the OCLT to determine if you need to shock. Turn off the SWG and keep the pump running all night.

If it is cloudy and your FC went to 0, then you likely need to do the shock process.

Use what your target was for the CYA including what you just added to determine the shock FC level.