Need Help Saltwater Pool Not Holding Chlorine

[IceShadow]

Add liquid chlorine. Perhaps there’s an issue with your SWCG?

 

[GordoMosley]

I appreciate you answering but I have been adding LC

 

[GordoMosley]

Tested this morning at 0530 5/19/21:
FC 6.2
CC 0.0 (maybe 0.2 but it looked clear to me from the start of the test)

Pumps and SWG have been off since 2300 5/18/21

From all my test and the weeks leading up this thread I keep losing FC during the daylight hours.

My CYA is in the 60-70 range. Water is crystal clear.

Any thoughts?

 

[GordoMosley]

I promise my pool is crystal clear. I just don't understand how to maintain the FC level. Something during the day keeps sucking up all my chlorine. =(

 

[mknauss]

That normally points to a CYA much lower than you are assuming.
Carefully do the CYA test in bright sun, sun to your back, etc.

 

[GordoMosley]

That normally points to a CYA much lower than you are assuming.
Carefully do the CYA test in bright sun, sun to your back, etc.

OK i will retest in sunlight. thank you.

 

[GordoMosley]

Retested this morning

pH 3.0
cc 0.2 maybe 0.0
CYA 50 (did multiple test with my wife and neighbor, lol)
TA 130
PH 8.0 (brought down to 7.7)

Thoughts? Is my CYA too low. Still losing a bunch of FC through the day

 

[IceShadow]

Have you tried turning off the SWCG and using liquid chlorine for a few days to see if you see the same drop with that? That should help to determine if something is wrong with the SWCG.

 

[GordoMosley]

Have you tried turning off the SWCG and using liquid chlorine for a few days to see if you see the same drop with that? That should help to determine if something is wrong with the SWCG.

SWCG is perfectly fine its a week old. if i run just the SWG at night my FC goes up. I have even captured return jet water and got readings of 1 to 2 ppm from the jet when SWG is running.

Done a overnight chlorine test and have passed multiply times with the SWG off. All lights are green on ic40 and its at 100%

 

[GordoMosley]

Should I raise cya?

 

[mknauss]

Should I raise cya?

You can. It is not urgent, but over the next couple weeks getting the CYA to 70 ppm would be a good idea.

 

[IceShadow]

It sounds like you should. I would raise it up to 70 - that's what's recommended as a starting point for SWCG pools. The only reason not to raise it is if you need to SLAM, but it sounds like your water is clear, you're not losing any overnight, and no CC, so no need for a SLAM.

 

[GordoMosley]

Ok I am thinking 60 to start see how it does then pop it to 70

Thank you guys!

 

[IceShadow]

Just be careful not to overshoot - you'd have to drain water to bring it down!

 

[ChasPro]

So similar for me this season ... How did this issue eventually resolve? Thanks.

 

[GordoMosley]

Forgot to follow up.

Raised CYA to 70 and pool now maintains a 6 FC and 0.0 CC; crystal clear.

To low of CYA was eating up my FC.

 

[ChasPro]

Thanks. I added CYA and it didn't go up ... but @mknauss pointed me to a "better way" to add ... so once we get past the SLAM, we'll see where the CYA settles out.

He is helping me over here if anyone gets this far and you're still stumped. My experience (still unfolding) may lead to something helpful:

Can't Get CYA (and FC) to Raise ... After Long Period of Filtering and Mystery Goo

I have had the worst time starting up my SWCG pool this season, with what seemed like just a slightly cloudy water situation in mid-May. Went through normal startup (pulled cover, filled with water from just below return jet to proper skimming level, added 2 gal liquid shock, ran for several...

www.troublefreepool.com