Uh oh- zero Free Chlorine with pool pilot nano +

[zimm]

I tested my pool pilot nano + today after finding zero chlorine in the pool. Salt 3400PPM, temp 87, duty cycle was 50% (bumped to 75%), and running 8 hours (4hrs morning, 4 hrs night). Cell is pulling 4.9 amps. 4600 amp hours life on the cell.

Pool tests:

7/17/15
PH 7.2
FC 9.0 (had pucks floating for vacation)
TA 70
CH 225
CYA 45

Added 4 lbs CYA, and 25 pounds calcium

7/23/15
PH 7.2
FC 0.0
TA 60
CH 325
CYA 55

Water is still clear. Did pool math and added 121oz of clorox and threw my tri-chlor puck floater back in.

My next idea is to pull the cell and check for build up. It's on it's third season and I checked it last summer and the plates were clean.

Ideas?

 

[zimm]

Sent from my iPhone using Tapatalk

 

[Austintatious]

Zimm,

Did you try testing some water from a return to see if your cell is making chlorine?

 

[pooldv]

When that happened to me a month ago I had algae. Behind the light, in the cleaner and a few little spots on some rocks here and there. My FC was 1.5. I had perfectly clear water for 3 straight years. I got lazy and didn't test the week we got back from vaca, just as it was heating up and we were swimming more. Had to swim-n-slam for a week and a half. CYA was 70, FC 25-28. Worked out pretty well.

Nice pool!

 

[zimm]

I checked FC this morning and it was 4.0. I also pulled a sample from the return and it was also 4.0. I should have checked that when FC was 0...

My walls have a yellow hew, so I decided to SLAM. With CYA of 55, I'm targeting 24. Dropped 64oz of 73% sodium-hypo in this morning and brushed the pool. I'll check it after work today. I have a pool party tomorrow so hopefully the kids won't mind SLAM levels of chlorine....

 

[pooldv]

Good plan! Keep FC slightly below shock level and swim away. We swam every day during our slam.

Keep in mind if you want to try to test water from the return that the SWG does not produce chlorine 100% of the time. Do you ever see little air bubbles coming from a pool return? Usually the first one in the loop. If so, that is your SWG producing chlorine.

 

[zimm]

Yup I do get little bubbles on the two main returns. Thought maybe I had a leak!

FC dropped from 24 to 15 during the day. Dumped two bottles of Clorox in last night. This morning the drop was much less, 21. That's with swg and floater operating too. I'll wait till after party today and raise above 24 again. Yellow on walls in nearly gone, must have been a layer of mustard algae that snuck up on me.

 

[pooldv]

Yep, I've been keeping my FC at 8-9 just to be extra safe. I'd rather just sit in the pool and do nothing than brush every day!