compupool CPSC48 Need help with the math.

[doublewide6]

FC 10
cc.5
ph 7.7
CYA 65 (I added to go to 75 a week ago and not seeing a change)
Hello,
When I bought my CPSC48 about 4 years ago it was rated at about 2.3 Lbs/hr. at a 24 hour run time. Now looking at discount salt pools website the output for my unit has been changed years later. Full Market Comparison of Salt Water Chlorine Generators for Swimming Pools According to discountSP it produces 1.28 lbs. per day. My cell is having trouble holding up this summer with all the hot weather and people swimming daily. I passed the OCLT and my chlorine dropped from 7ppm in the morning to 5ppm at the evening. I usually have the pool covered with the solar cover and that really helps the swg produce, but with the really hot stretch of weather it has been uncovered. My question is how much chlorine should this thing produce on a 12Hr. run time, and how much FC will a full sun 22K pool burn through? I can see the unit is producing chlorine.

 

[YippeeSkippy]

I think you should first turn the SWG off tonight and perform an Overnight Chlorine Loss Test to determine if there is something in your water chewing up that chlorine. Directions --> Overnight Chlorine Loss Test

Make sure you test again tomorrow morning before the sun rises on to the pool (which would skew the test).

You may very well have a low level algae bloom being kept at bay by the chlorine....

 

[doublewide6]

Great minds think alike, I was planning on doing the OCLt tonight as well. Anyone else out there have some information on how fast 1.28 Lbs per day of chlorine is consumed in a day? Thanks

 

[mas985]

At a CYA of 65 ppm, you should lose less than about 50% per day. If the unit runs 12 hours at 100%, it should add about 3.6 ppm. So if your normal FC is 10 ppm, that means you would lose about 35% per day which is reasonable. BTW, you really don't need 10 ppm with a SWG. At 65 ppm CYA, you really don't need more than about 4 ppm.

 

[doublewide6]

Thanks Mas985. I'm running my swg at 70% for 12hrs. I have been trying to keep my FC at about 10 at the end of the day because I had an algae outbreak in the beginning of July. I try not to run the swg at 100% due to overheating (I have read on here about compupool units melting), so I should be producing about 2.5 FC per day if I'm running my swg at 70% (12hrs). I'm thinking I'm going to try and target between 6-8.5 FC, and see if it holds. Also, how do you convert lbs. of chlorine gas into FC? Thanks

 

[mas985]

To get ppm of FC, take the lbs of chlorine gas added during the runtime and % and divide it by the lbs of water = 21500*8.34

or

ppm = 1.28/24 * hrs runtime * pct / (21500*8.34)