Jandy APURE700 and cell life


Nov 20, 2009
How will I know when the cell is ready for replacement? Will I simply get an error code on the controller or is their some particular symptom I should be aware of? Can checking the resistance between the two cell contact pins (with water flow of course) with a multimeter give me any useful information about the condition of the cell?

The beginning of July will begin my APURE700's third year. I run the pump eight hours a day during the summer and all levels are about within normal range except I've been having difficulty maintaining the total chlorine and free chlorine at a high enough level. The first two summers I ran the cell at about 75-80% throughout the summer and it maintained the chlorine levels fine. We haven't had any unusual conditions and matter of fact although we're in our rainy season, I've had relatively little rain fall at my home the last several weeks. I've been running the cell at 100% eight hours a day for four days and finally yesterday set it to run a full 24 hours straight at 100%. The chlorine levels are still low, results listed below. The previous two years I've had to add a little acid every week or so when we get rain but its been easy to maintain the pool. Lately I'm struggling with the chlorine and I keep getting light green algae on the pool walls that get more sun.

I've used test strips, a regular test kit, and testing at my local pool store to confirm the results. They're all within the same neighborhood. I've got a DE filter which I disassembled and fully cleaned a couple of months ago just before summer. Pressure at the filter is the same the day the pool first went into service, about 14 psi. The cell had a very small bit of visible mineral deposits when I cleaned the filter so I soaked the cell in 1 part acid and 5 parts water for about twenty minutes to clean it.

Pool use has been pretty light the last few weeks with my nine year old in maybe an hour every other day.

Inground 10,750 gallons
Water temp is around 84°F
Salt 3.2 ppm
Total Hardness around 250 ppm
Total Chlorine 1 ppm
Free Chlorine 1 ppm
pH 7.2
Total Alkalinity 120 ppm
CA 80

It just doesn't seem I'm getting the chlorine production I should be although I've got no trouble indicators at the control panel.


TFP Expert
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May 7, 2007
Silver Spring, MD
When the cell is failing you will start to get service codes indicating low current.

I suspect you have a higher than normal chlorine demand, that the SWG can't keep up with. There are two ways to verify this. One is to do an overnight FC loss test with the SWG off to see if there is excess chlorine demand. The other is to test the SWG to make sure it is producing chlorine. You can test the cell by catching some water coming from the cell while the cell is on and comparing it's FC level to the level in the pool. You can catch some water from the cell either by taking a sample from a return jet, or by loosening the union on the output side of the SWG just enough to get a small stream of water coming out and test that.

If there is excess chlorine demand or the SWG is producing chlorine, you should shock the pool.


Nov 20, 2009
JasonLion said:
I suspect you have a higher than normal chlorine demand, that the SWG can't keep up with.
I suspect that may be it. I've only been shocking the pool by using the boost mode on the SWG. It simply sets the output to 100% and I run the pump for 24hrs straight. Admittedly I probably don't shock as often as I should, its more of an afterthought because the pool usually looks so good. I guess I have a more reactive than proactive personality.

Its been hot here and I cleared a few branches from overhanging trees a few months ago. The pool is getting a little more direct sun than it used to so the algae issue is probably the root of the problem along with me not shocking it adequately.

Anyway, a friend yesterday mentioned that my APURE700 might not have adequate capacity to properly shock my 10,750 gallon pool under some circumstances and I should shock with one of those one pound shock packets that are sold. Is it okay to use those with my SWG?

I've also since found a troubleshooting guide for my SWG after searching the forum a little more so I can test the system accurately. I have a bit of a basic electronics background so handling a multimeter isn't an issue.