I bought this swg for my Intex 18x48 pool with a 4000gpm Hayward pump which is the max they say the unit is good for. My problem is my chlorine level dwindles over a few days to the point I keep getting algae (FC was 2ppm last night). I tried the unit with cya levels from 30-60 and still keep having problems. Salt levels are 3200ppm. When ever I get the algae I SLAM the pool and start over by increasing the run time from the recommended 4 hours to now 9 hours of run time and it doesnt help. Does anyone else have this problem. Does anyone know if reducing the water flow (maybe install a valved/chokeable bypass) to slow the water down through the unit might help? I never had this problem with the older style Intex SWG.
Trouble with Intex Intex Krystal Clear Saltwater System and Ozone Filter
- Thread starter gtty
- Start date
Ideally you want your CYA level at around 75 for the SWG to keep up. Try that and make sure the cell is clean in the SWG.
The documen tation states that the CYA should be 30 and maintain the FC @ 0.5 - 3ppm
"Test the pool water every week to maintain the proper sanitizer level.
It’s very important that the free chlorine is between 0.5-3 ppm."
I wonder if the water is running too fast through the unit, somewhat similar to air travelling too fast across and a/c coil doesn't remove enough humidity.
"Test the pool water every week to maintain the proper sanitizer level.
It’s very important that the free chlorine is between 0.5-3 ppm."
I wonder if the water is running too fast through the unit, somewhat similar to air travelling too fast across and a/c coil doesn't remove enough humidity.
From the Manual
Preferred Water Chemistry Reading
Free Chlorine min 0 Ideal 0.5 - 3 ppm Max 5.0 ppm
Combined Chlorine min 0 Ideal 0 ppm Max. 0.2 ppm
pH 7.2 7.4 - 7.6 7.8
Total Alkalinity 100 ppm 100 - 140 ppm 140 ppm
Calcium Hardness 150 ppm 200 - 400 ppm 500 - 1000 ppm
Stabilizer (Cyanuric Acid) 10 ppm 20 - 40 ppm 50 ppm
Preferred Water Chemistry Reading
Free Chlorine min 0 Ideal 0.5 - 3 ppm Max 5.0 ppm
Combined Chlorine min 0 Ideal 0 ppm Max. 0.2 ppm
pH 7.2 7.4 - 7.6 7.8
Total Alkalinity 100 ppm 100 - 140 ppm 140 ppm
Calcium Hardness 150 ppm 200 - 400 ppm 500 - 1000 ppm
Stabilizer (Cyanuric Acid) 10 ppm 20 - 40 ppm 50 ppm
The manual is wrong. The pool industry does not get the water chemistry right in almost all cases. Crazy, I know! 
Here is how TFP recommends to balance a saltwater pool.
Pool School - Water Balance for SWGs
Here is how TFP recommends to balance a saltwater pool.
Pool School - Water Balance for SWGs
so a CYA of ~10ppm less will allow my chlorine level to drop that far when running the unit more than twice as long as recommended? I'm starting to wonder if it's defective. I've been running since June 3 of this year and the chlorine levels have always been dropping and I've had to supplement with bleach to keep them up.
Yes, CYA of less than 10 will allow your chlorine to be burned off by the sun in minutes. Also, algae can use up that much FC in a short amount of time too. Use bleach to help the SWG keep the FC at target. To check for algae raise the FC to 10 and Pool School - Perform the Overnight FC Loss Test (OCLT).
The times I SLAMed the pool and always followed OCLT. My CYA is 10ppm less than 70 (60ppm), not 10. Still with the unit running more than twice as long, I'm surprised it doesnt keep up.
Pooldv has got you covered. Here is a link that may help you.
Pool School - Chlorine / CYA Chart
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And another link.
Pool School - Water Balance for SWGs
Pool School - Chlorine / CYA Chart
- - - Updated - - -
And another link.
Pool School - Water Balance for SWGs
Ok 60 CYA isn't too bad. Have you checked the cell for calcium build up or cleaned it recently? If the cell is clean then the only thing that can be consuming your chlorine that fast is algae.
Here they are http://www.marineinsight.com/wp-content/uploads/2013/11/pumps.jpg
OK 4000 gpH only off by a factor of 60
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I have had this problem since I bought the SWG. I started at their recommended CYA level and have been increasing it. Everytime I increased the CYA, it was asfter a SLAM and OCLT. It takes a little over a week and a half for the chlorine to drift down and Algae to bloom. I'll get some fresh numbers from the test kit and repost.