chlorine output

[Donna's Poolboy]

I've had my Auto pilot (SC-48) running for a little over 2 weeks now and I have a question about the amount of chlorine it's producing. I have it set to run for 12 hours (7p-7a). I'm at 50% on power level 3, yet it only raised the free chlorine level by .5 ppm. Here are my numbers:
cc 0
fc 2.0
ph 7.2
alk 80
cal 150
cya 60
salt 3500
When I run the test on the auto pilot, it shows that it's running at power level 3; 29v 6.8a, minerals 3300.
My cya is still low, but I just added 2 pounds yesterday so I'm still working at getting to 70-80 ppm.
I haven't seen that spike in ph that I've heard about with SWG's...but my pool is vinyl. With the alk at 80, do I dare try to raise the ph?

The pool loses between 1 and 2ppm of cl per day. I started at the lowest power setting as the instructions suggested, but I was still having to add cl. Same thing at level 2 and 50%. I've been at level 3 50% since Tuesday so I'm not sure yet if it's keeping up with the pool's cl demand. Still, isn't that a low amount of cl being produced? Am I shortening the cell's lifespan by operating at that level?

Thanks,
Bill

 

[JasonLion]

Raising the CYA level will help you maintain a higher FC level. You can also turn up the percentage further.

It is also important to test your FC level at the same time of day each time, preferably in the early evening. The FC level will fluctuate somewhat over the course of a day, depending on the amount of sunlight falling on the pool. Testing in the early evening is usually the time of day when the FC level is lowest.

One possibility, is that you have just the start of an algae bloom, where the SWG can never quite catch up and kill all the algae. To test this you will need to turn off the SWG for one night, measure the FC level in the evening, and again the next morning. If your FC level falls by more than 1 overnight, then you have algae, or some other organic contamination in the pool and need to shock the pool.

 

[Poolsean]

By your cell amps and volts, it sounds like a few possibilities.
1) Remove and check your cell for calcium scale on the blades.
Clean if necessary.
2) Verify your salt level with a separate salt test.
Calibrate the unit to match your test result if necessary.
3) Your water temperature is cold (below 65 degrees)
If you have a heater, turn it on.

You should be around 8 amps on Cell Power 3, 6.5 amps on Cell Power 2, or 5.0 amps on Cell Power 1.
Any one of, or combination of the above will cause the voltage to rise to 29 volts, at which point the amperage will drop (which you've indicated).
If you're actually below 2800 ppm of salt, increase it to about 3500 ppm, especially if the water is still cold.

 

[Donna's Poolboy]

Thanks for the responses guys--
I added 1.75 lbs of cya yesterday.
Sean-
My unit is brand new this year and has been running a little ove two weeks. I checked the cell anyway and it looks brand new--no build up, scaling or obstructions. I just ran a second salt test (using AquaCheck strips) and the reading is 3880 ppm. The Autopilot reads 3300, so I'll calibrate it to reflect 3900. The water temperature is 82 (Autopilot is reading 84) and it's been in that range for the last 2 weeks. The power reading is level 3, 29v, 6.7 amps.

Is there anything else to check, or do I have a more serious problem?

 

[Poolsean]

Change the Cell Power to 2, let it run a few minutes in BOOST, then run a TEST POOL PILOT.
Do the same at Cell Power 1.
Let me know what you get.

To avoid cluttering this post, E-mail me off line. [email protected].
Once we determine what's happening, we can summarize and share with everyone else.

 

[JasonLion]

I am thinking this must be a low level algae bloom held in check by the SWG. If you have a chance to do an overnight FC loss test with the SWG off, I think that will be very interesting.

 

[Poolsean]

Hey Jason,
That would be a good test to find out why the chlorine is not holding. However, my focus is the operating amps and volts. It's just not in the right range, with no apparent reason.