SWCG "strange" behavior? (or not...)

[EdKuhn]

I have an Intellichlor IC-40 SWCG, newly purchased at the beginning of this season. After I got everything dialed in (I had to do a SLAM early in the season) the pool was humming along reading 10ppm FC consistently, SWCG set at 40% output. Since I had consistent readings of 10 (and sometimes 11) ppm FC, with periodic passing OCLTs, to extend the life of my SWCG I reduced the output to 20% in early August. The FC readings then dropped to 8ppm. All this time I could have sworn that the "status" light was green the entire time. Fast forward to a week ago. I was in the pool pad area doing something and noticed that the status light was off. This struck me as "different" and this is what made me think that status light was always green previously.

Conducted FC test and saw FC was down to 7ppm (0 CC). Monday, 6.5pppm (0 CC). Tuesday down to 5.5ppm (0 CC), and on Wednesday of this week I conducted an OCLT. Stayed at 5.5ppm, zero CC. Pool is still crystal clear. Turned generator back to 40% output. Last night I stood at the pool pad and timed the amount of time that the status light was on and off. Exactly 40% on, 60% off (over a 5 min period). So the SWCG is operating as it should, being set at 40%. Tested FC this morning, FC now at 6.5 ppm, 0 CC. I should add the pool gets full sun for most of the day.

So my question is - was the SWCG really generating Cl all the time for the past 3 months? (30% of the life of the generator, yikes!) Is it possible for it to suddenly start operating the way it was intended (i.e. cycling on and off as set?). Why else would the FC level drop, with a good OCLT? Maybe the hot weather (water temp is around 88 degrees)? Or, am I just going a little nuts??? (or not as observant as I think I am haha)

Current test results

FC 6.5
CC 0
pH 7.6
TA 75
CH 250
CYA 80

 

[mknauss]

I would suspect the SWCG was operating correctly the entire time.

You do not state pump run time but I am going to assume 24 hours. As that would equate to 2.2 ppm FC added each day when the IC40 was set at 40%.

Would seem to me everything is operating normally.

You might consider a two speed or VS pump in the future to reduce your electrical cost.

 

[YippeeSkippy]

You must remember....its August! HOT muggy August is going to challenge any SWG at times if you've had a lot of swimmers, a lot of sun, etc.

I would bump up the % back to 40% and monitor as usual. Come September, October you'll be turning it down some...

Maddie

 

[Jimrahbe]

Ed,

I agree with Marty, your cell is working just fine.. The problem is you..

Without an automation system, the IC40 can only be controlled in 20% increments... So 40% was a little too high and 20% is way to low. The only other way to control the chlorine output of the cell is by adjusting the operating hours of the pump.

Thanks,

Jim R.

 

[EdKuhn]

nah, nah, CANT be ME yes the pump runs 24 hrs. When it's time for a new one I'll get a 2 speed (and the utility will give me a rebate)

Thanks for the replies everyone. I get a little OCD sometimes, especially about the pool (and motor oil but that's another topic for another board)

 

[sgoosman]

Hi Ed,

Reading the thread, your last post surprised me. You are running a 2hp motor 24/7 to clean your 30K ig pool? My first concern for your is wasted electricity cost. The average 2HP single speed pool pump should consume around 2.25KW of electricity per day. If your run your pool 24/7 and electricity is about $0.11, I'd expect your spending about $178/month. If you keep your pool open 6 months/year total spend is $1069.

Next if you have 60ft head on that pump your flowrate is around 76 gal/min which means suggests your filtering upwards of 109K gallon/day. I'm sure this keeps your pool sparkling but this it's probably excessive.

Switching to a variable speed pump and lowering your flow will save you a lot of money. Assuming a 70% reduction in cost, that is a savings of $124/month in your electricity bill. I don't yet have a vs pump, it's in the mail, but these savings almost necessitate switching to a VS pump to stop wasting electricity and money. Feel free to check my assumptions too, Power (kw) = Voltage x Amps which should be listed on the motor plate for your own calculations.

-Scott

 

[duraleigh]

In your situation, a 2-speed 1.5 HP should give you plenty of vacuuming power (if you needed it) and pay for itself, literally, in the first year.