The initial salt pour was about 4 months ago and the pool is 5 months old. 26,500 gallons. The chlorine levels keep dropping to near nothing. I've turned the SWG system dial up from 50% to 60, then 70, then 80. I get higher chlorine levels for a few days, then it drops to nothing again. Do I need to add more salt? The SWG level shows a consistent 3300-3400.
Salt pool - Low Chlorine Levels
- Thread starter tedujam
- Start date
Others will chime in but I think your salt level is just fine. You may need to increase your pump run time. They say it's better to increase the pump run time and turn down the SWG a bit so that the cell will last longer
- May 23, 2015
- 24,381
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
What are your water temperatures? Most of the SWG's have a cold water cutoff and stop producing chlorine when the water temp is below 58F. It could be that your water is warming up slightly during the day and your cell is only able to generate chlorine when the water warms. Most people that live with "year-round" pools switch to manual chlorination in the winter months.
However, because it is also cold, your chlorine loss rate should be very minimal. I only lose maybe 0.1-0.2ppm FC per day. If your FC is at target levels and then drops to 0ppm in less than a day, then you might also have an algae problem. You can test that by doing an overnight chlorine loss test (OCLT) - Pool School - Perform the Overnight FC Loss Test (OCLT)
However, because it is also cold, your chlorine loss rate should be very minimal. I only lose maybe 0.1-0.2ppm FC per day. If your FC is at target levels and then drops to 0ppm in less than a day, then you might also have an algae problem. You can test that by doing an overnight chlorine loss test (OCLT) - Pool School - Perform the Overnight FC Loss Test (OCLT)
Can you provide us with some test results please? You could possibly have an algae issue.
+1 on the cold water. Mine stops acting right a little below 70. I turn mine off and switch to bleach. I test weekly and keep FC at 10ish.
I had a similar situation earlier in fall, and it turned out to be an algae bloom in my light niche. SWG was doing fine, but the chlorine was being used up by algae. Just another possibility, been there, done that. SLAMmed it, all went back to good levels. Now I'm not producing CH due to water temps being low, but I can wait that one out.
Thanks, that's probably it. My water temp is between 50-60 most days. I didn't realize the SWG stopped producing chlorine at a certain temp. Can you adjust the temp threshold?
I really don't want to go back to dumping bleach in the pool every other day.
- May 23, 2015
- 24,381
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Sadly, no. The purpose of that cutoff is to protect your cell. Electrolytic chlorine production is temperature sensitive. As the water temp drops, the efficiency of the chlorine production falls off and you can actually damage your cell if you try to run it with cold water.
Most people just manually chlorinate in the winter because your daily FC loss should be very low. If you are experiencing an excessive chlorine demand in the winter, then you may have an algae problem (yes algae does grow in cold water, just very slowly).
For example, I have manually added bleach three times to my pool since the SWG stopped running in late November.
Sent from my iPhone using Tapatalk,16k gal SWG pool (All Pentair), QuadDE100 Filter, Taylor K-2006
Last edited:
I test once a month or so and usually add a gallon or two. I try to get FC back above 10ish. I have also probably added 3 times since shutting off the swg.