Cloudy, but FC=1.0 and CC=0

NYkidney

Member
Jun 1, 2019
8
Endicott, NY
Still new to this, so please bear with me.
Pool has been doing great for over a month. Crystal clear water and chemistry good.
I noticed it starting to get cloudy yesterday, and it's the same today. Can see the main drains, but not real well.
I hope my info will show in my signature...
Yesterday FC was 3.0. I tested earlier today, and FC=1.0 maybe 1.5. CC was 0.
Ph was down to 7.2 yesterday, and I added 32 oz of Borax.
My CYA was down to 60 yesterday, and I added 15 oz of stabilizer (I tend to go at this slow, so I had 1/2 the recommended amount)
CH=240 (but vinyl liner, so...)
TA=80
Salt=3000
Temp=85

In case it doesn't show below, it's a 15,000 gallon IG, sand filter, SWG
I admit I had the SWG turned down to 20s because my FC had been high. I probably let it drift too low.

With FC above zero, should I try to SLAM? I added bleach and turned up the SWG to 100. Plan to continue to run filter 24/7 (was already due to addition of stabilizer).

Thanks in advance.
 

justinc

Gold Supporter
Apr 3, 2019
591
Texas
If your CYA was 60 and you added additional, assume you are now closer to 70. For 70 CYA in a salt water pool per the FC/CYA Chart, your free chlorine level is not supposed to ever drop below 3. Since you have water clarity issues and low chlorine there is a high chance of algae and you'll need to SLAM. Your SLAM chlorine target is 28.
 

NYkidney

Member
Jun 1, 2019
8
Endicott, NY
I understand pH testing isn't reliable during SLAM, but what about CYA.
I just put in a bunch of bleach to start the SLAM, and tested an hour or so later. The FC level was 19, so I had to add more than I thought (per PoolMath). I had absolutely no CC. I thought I'd test CYA, to ensure I was shooting for the right FC level -- since I had CYA=60 two days ago (I said yesterday earlier, but checked my logs) and added 15 oz of stabilizer (two days ago). I expected that to bring me up to close to 70. when I tested today, just now, it was barely 60. Maybe it's still on the way up. There was just a very little left in the sock by yesterday afternoon.
I'm probably not alone, but that test is so subjective - it drives me crazy. I'd kill for something more evident, like the other tests.
 

justinc

Gold Supporter
Apr 3, 2019
591
Texas
Combined chlorine won't always show up... especially if the pool has been getting a lot of sunlight.

If you tested your CYA and got 60 and are confident all the CYA has dissolved out of the sock then you can use that value. I do agree that the CYA test is the hardest of all of them to really get confident at performing. I usually fill to the first mark, glance at the dot, fill to the next, glance, and so on until I can't see the dot at first glance. Do this in normal sunlight with your back to the sun. I have found this method really helped make it easier for me.

You can test the CYA level at any time. Just don't adjust during the SLAM because you then change your target goals.
 

NYkidney

Member
Jun 1, 2019
8
Endicott, NY
Thanks for the CYA advice. I'll give that a shot. The idea of "at first glance" makes a lot of sense. When I'm staring at it, my mind plays tricks. I'll do it 3 or 4 times, too. I do stand with my back to the sun.
I swear the deep end looked a little clearer just now. I'm going to wait another hour or so and then test for last time today -- and see how I do with OCLT tomorrow morning.
Thanks again for quick responses!
 

justinc

Gold Supporter
Apr 3, 2019
591
Texas
Your SLAM won't take very long, but just make sure to do it right and don't stop until you meet all criteria (CC <0.5, crystal clear (like gin!) water, and pass the OCLT). Then just don't let you free chlorine drop so low again.

When adjusting your salt water chlorine generator, start out high and gradually go down. A little extra is no big deal but not enough = cloudy pool.
 

NYkidney

Member
Jun 1, 2019
8
Endicott, NY
newbie mistake. Won't happen again. Clear like gin... now I need a drink!
I have a feeling might have an issue with my cell. But I'll watch it closely and see. One thing at a time.
 

NYkidney

Member
Jun 1, 2019
8
Endicott, NY
SWG was off, water is very clear this morning, OCLT was basically zero, and CC is also basically zero.
FC was 27, figuring that my CYA would be near 70 (read that if I've added stabilizer, then use the calculated target and not actual reading for several days).

1. Should I leave the SWG off until the FC comes back into range (or close to it)?
2. How long might it take for FC to drift back down? Very sunny and hot here the next few days.
3. Just want to verify that it's safe to swim at this point. True?
 

CarolineM

Silver Supporter
Jun 20, 2018
220
Annapolis, MD
You can turn your SWG back on now.
The higher the chlorine level the faster it drops, it will burn off some today and continue to burn off
It is safe to swim up to your slam level based on your CYA as long as the water in the deep end is clear enough to see the bottom.

Happy 4th