AquaPure 1400PLC generating less chlorine than last year - no error codes


Jun 30, 2016
Oakville ON, Canada
I've got a vinyl salt water pool with cartridge filters and a two-year-old AquaPure 1400PLC. Last year I ran it at 30% with the pump running an average of 12 hours a day. Chlorine levels were fine (1-3 ppm) all summer without shocking. I started this year by running it at 50% for 12 hour per day, but was getting very little chlorine (test showing about 0.1 ppm, which I assumed was residual from shocking a few days prior). I spoke with a pool company owner who suggested that, with the very hot sunny July we had, the chlorine was burning off very quickly. At his suggestion, I boosted my stabilizer (cyanuric acid) level (to about 60 ppm) and ran the AquaPure at 100% all day for a full five days. This brought my chlorine level back to a bit over 2 ppm. At that point, I set the AquaPure to 70% and set my pump to run for 12 hours a day. Testing it today, less than 72 not-very-sunny hours later, I had very little chlorine. For now I'm back up to 100% with the pump running 16 hours a day, hoping the rectify it.

It hasn't given me any error codes and the controls appear to show it functioning properly. The unit itself is clean with no apparent scaling. My salt level is somewhere between 2800 and 3800. I say that because I had two pool shops test the same water sample and they came back with results 1000 ppm apart. My system shows about 3600-3700 ppm usually, but I recall that has to be calibrated and I've not done so this year. Stabilizer is about 60 ppm; pH, hardness, and alkalinity are fine.

Any thoughts? At what percentage do you run your AquaPure? I find it odd that 30% worked last year, but this year seems to require 100%.


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
The vast majority of issues you describe are chemistry related. A SWCG cannot out run an algae bloom.

What test kit do you have? Can you post a full set of test results?


Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
Bedford, TX

The problem is not your SWCG, the problem is you have algae.. You either have algae or you don't.. There is no such thing as a tiny bit of Algae..

Your FC is way too low for your level of CYA.. See the saltwater section of this chart for the target level you should be keeping your FC. FC/CYA Chart


Jim R.
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