Re: Newbie - Help

Originally Posted by
sw_stupid
All right I'm gettin this. Is there a tell tale sign that my SWC cell is on the blink? How will I know? I think the display is wrong on the salt level, but I'll find out when the kit gets here. My confusion with salt level and the SWC is this: If the display says 2700 and the test says 3500 (which is what the pool store says) which does it use to generate? If it generates based on its display, that explains the low FC. If it generates based on the actual level, which is much higher, then the chlorine is going somewhere - or the cell sucks, or something. I sure hope these things last longer than 3 years, but who knows. Gettin bleach tonight and ordered Ben's kit last night. Should be just a matter of time now.
Thanks in advance for the answers,
Brad
I apologize for the length of this post but you have a lot of questions that I might be able to answer and I have some advice that you are free to follow or ignore
First is to get a good drop based test kit that will also measure salt levels.
It will become your best friend!
Check out this thread
http://www.poolforum.com/pf2/showthread.php?t=151
(think of it as your socket wrench set, timing light, sparkplug gap gauge, etc. for your pool...can't live without it when doing a tune-up!)
The display on the SWG is actually a measure of the conductivity of the water. This will change with temperature, pH, and how much scale is built up on the cell. It also can be 'off calibration' and give an inaccurate reading. IF the pool store is using a drop based test I personally would believe that over the display on your cell. If they are using a salt test strip then I would assume that your salt level is higher than your readout and might be as high as the pool store says (precision of salt test strips tends to vary with the salt level). If they are using a meter to read it, well the display on the meter is actually a measure of the conductivity of the water. This will change with temperature, ph,....etc., etc., etc.
IF (and it is a big IF) their meter is calibrated you can trust their reading. Problem is, can you trust their answer when you ask if they check the calibration of the meter on a regular basis?
The readout of the salt level has nothing to do with how much chlorine the cell is generating. That is set by the percentage of time the cell is on each hour of run time. Keeping your salt level at the higher instead of the lower end of the range will lengthen the life of your cell because it won't have to work as hard to produce chlorine. When the cell dies, from my understanding, it will usually just stop working. There might be some decrease in output as the cell ages but, once again to the best of my understanding, it should not be that significant. (Poolsean or Mark_Watermaid please jump in and correct me if I'm wrong here!)
Now, my 2 cents on where your chlorine is going.

Originally Posted by
sw_stupid
The pool is very clean, BUT it is not yet crystal clear like it always has been. I assume it is the lack of FC, but I don't know what to do. I have tried the "super chlorinate" shock feature twice now with limited results. The FC will go up for a day or so but then go back down. I also have a small amount of green algae trying to form on the walls.
You have cloudy water and some algae growing. This means you have a chlorine demand and the FC is being used up fast. You never posted your Total Chlorine readings (or if you did I missed them and apologize in advance). They would be illuminating because I would bet that they are higher than your FC. The superchlorinate setting is NOT the most efficient way to shock your pool and will only shorten the cell's life!
I would listen to Duraleigh and use bleach (sodium hypochlorite, exactly the same as "liquid chlorine" or"liquid shock" from the pool store except, maybe, for the concentration) and get your Cl up to 16-18 ppm and keep it up there until the pool clears. He and I are on exactly the same page here! I am willing to bet that the superchorinate setting just never got your FC levels high enough to take care of the problem. Bleach will do the trick and not shorten your cell life.
I don't think your cell is on the blink. It IS generating chlorine, just not enough (or enough fast enough) to take care of the temporary demand in your pool.
I am wondering where you got the CYA reading of 42. that sounds like a pool store reading and if they are not using a liquid or power reagent with a properly calibrated colorimeter/turbidity meter I would be suspicious of it. If they are using a drop based kit then there simply isn't that much precicsion in the test to give a reading of 42. We won't even talk about test strips!
Duraleigh was right on the money again when he said that Goldline controls recommends the CYA between 60-80 ppm. I have an Aqualogic ps-8 and run mine there. Works great!
Final thing, If you could post a current set of test results that have FC, TC, pH, ALK, CH, and CYA, and salt that would be most helpful in really getting a handle as to what is going on!
Final final thing. Take some time and read through the forum and the sister website www.poolsolutions.com
You will find a wealth of info and lots of help and helpful people. I bet in no time you will be changing your "nickname" to sw_smart
It really ain't rocket science!
Edit: Just reread through one more time and something jumped out at me. You closed your pool for the winter and had no circulation (pump off). I am wondering what was the CYA level when you closed?
If it was higher than when you opened then it would help explain the chlorine demand you are seeing. Also did you add any CYA when you opened the pool to get it up to the reading of 42 that you posted?(ok, maybe semi-rocket science)
Last edited by waterbear; 05-04-2006 at 08:08 PM.
Retired pool store and commercial pool maintenance guy.
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