Hello, first I want to thank this forum for the great advise I have read that helped me successfully maintain my pool. Now for my question: I think my Intex SWG system is malfunctioning, but I want to make sure I am not missing anything with water balance before I contact Intex (it is still under warranty). Details are as follows:
Pool=16ft diameter x 4' deep above ground pool (5000 gal.)
Pump/filter/SWG= Intex CG-28675 (Saltwater system with E.C.O.)
Salt=3400ppm (was 2800ppm when problem started. I increased it to 3400ppm to see if that would help, but it didn't)
Temperature=85 deg F.
Chlorine=1.5ppm max using SWG (Usually 1.5ppm FC/0.0ppm CC, but sometimes 1.0ppm FC/0.5ppm CC)
I set this pool up the beginning of last summer and it has been up and running ever since. Up until the beginning of May this year, the pump has had no problem maintaining my desired Free Chlorine (FC) level of 6.0ppm. Last summer during May thru August, it required 5-6 hours of run time to maintain a 6.0ppm FC level. At the beginning of this May, my FC levels fell to near zero. I am currently running the pump 8 hours per day, but the chlorine still stays at 1.5ppm. I would run it for longer, but based on my logs (past history) 8 hours should be more than enough. At least I would expect higher levels of Chlorine than 1.5ppm with 8 hours runtime, but no such luck. I usually test for chlorine using the FAS-DPD method, but I also tried the OTO method. I also tried new DPD powder, but that made no difference in the test readings. I tried replacing the electrode but that did not improve things. The electrode is producing bubbles, but I don't know how the amount of bubbles compare to when it was operating correctly. Also, the electrode seems to develop deposits on it quicker than it used to. I currently need to clean it at least once a week. I am getting no errors from the pump. In the past, if the electrode got too much buildup, I would get a low salt warning. There have been no similar warning since the problem started (hopefully because I am cleaning it often enough). Also, I am getting plenty of flow through the filter, so that isn't the problem
I also did some tests at the electrode with my digital multimeter. The open-circuit voltage at the connector (voltage at plug, disconnected from electrode) was 11.63VDC. When connected to the electrode, the voltage is 9.17VDC and the electrode current is 3.0A. I have no idea what the values are supposed to be. I wish now I had tested that when the pump was new to get a baseline to test against.
So those are the details. Are there any more tests I should do? Is there something with the water chemistry that could interfere with the chlorine generation? Thankfully, the combined chlorine (CC) has stayed below 0.5ppm, and I can use bleach to maintain the pool, but I need to get this SWG problem figured out. What do you think?
Thank you so much!