New SWG install - Salt level Questions

[scott407]

I have a brand new SWG install. The K1766 test kit shows 2600, the Aquarite strips that Hayward sent with the salt system show 2580 and the salt system says 3000. I know there is a margin for error in all of them. I am struggling with adding more salt to get closer to 3200. My FC is at 6.5 running the chlorinator at 100% for 14 hrs. According to the SWG calculator, a pool my size 34400 should have 14.1hrs of runtime to maintain 3.0 FC.

When I added my salt initially everything I read showed a need for about 26 bags of salt. I added 15 to get to where I am now. Could my pool volume be off that much?

The pool is 40x20, 8.25ft in the deep and 3.25 deep in the shallow. (5.57 avg. depth) which brings it to 34400 or 34500(depending on how you round).

The k1766 showed salt readings at 3200, 3200, and then 3400 yesterday. Can surface water be less diluted than deeper water or water from the returns?

I changed the timers to run the SWG 12 hours to see if the FC level changes tomorrow morning.

 

[ajw22]

If your cell is generating and not indicating LOW SALT then your salt level is good.

Did you test your water for salt before starting to add salt? Unless it was fresh water most pool water have salt already.

Do you have a problem you are trying to fix?

 

[Mr Bruce]

Did you measure your salt level with the K-1677 before you added salt? You probably had somewhere in the neighborhood of 1000ppm before you even added more, depending on how long ago the pool was filled.

If the SWG is generating chlorine, I wouldn't worry about adding more salt.

The K1766 is +/- 200, so 3200-3400 is fine. I would probably use the higher number since salt (almost) always goes up.

 

[scott407]

Thanks for the replies. I always am able to count on this group for guidance.

Did you measure your salt level with the K-1677 before you added salt? You probably had somewhere in the neighborhood of 1000ppm before you even added more, depending on how long ago the pool was filled.

If the SWG is generating chlorine, I wouldn't worry about adding more salt.

The K1766 is +/- 200, so 3200-3400 is fine. I would probably use the higher number since salt (almost) always goes up.

The salt was at 460 to 520 (according to the strip test) I did not have the k1766 at that time.

If your cell is generating and not indicating LOW SALT then your salt level is good.

Did you test your water for salt before starting to add salt? Unless it was fresh water most pool water have salt already.

Do you have a problem you are trying to fix?

I'm trying to avoid the problem of having to dump and replace water. I learned early on that "adding all of the chemicals" called for at one time is not the best practice. Thats why I added only half of the salt called for by the charts. Using liquid chlorine I was able to maintain my pool on auto pilot. Being new to the SWG pool I just want to make sure I don't screw it up.

Specifically, my salt level is showing 2600 this morning, but 3200-3400 the day before and everything I've seen says 3200 is the magic number. The confusing part is that although my salt levels seem to fluctuate 600+/-, my FC generation is double (6.5) what it should be (3.0) using the SWG Calculator I found here.

Can surface water be less diluted than deeper water or water from the returns?

 

[ajw22]

The magic salt number is whatever keeps the SWG generating as long as the K-1766 says it is below 4000-4500. The salt level once generating has little effect on the FC output. So move on from focusing on the salt level to why your FC output is not what you expect.

Your signature does not say what cell you have. Share your calculations.

 

[scott407]

Here is a screenshot from the calculator. When I initially added the salt there was a check system warning because the levels exceeded 4000 ppm. Once the salt was distributed it went back to normal.

==========================================
Scott Pool
------------------------------------------
Build Type: Vinyl
Volume: 34400 gallons
------------------------------------------
Latest Test Result Summary:
FC: 6.5 (2 hours ago)
CC: 0.0 (2 hours ago)
pH: 7.5 (2 hours ago)
TA: 90 (2 hours ago)
CYA: 60 (yesterday)
SALT: 2600 (2 hours ago)
TEMPERATURE: 83° (2 hours ago)
==========================================
------------------------------------------
Test Results 05-29-2019 @ 07:14 AM
------------------------------------------
Free Chlorine: 6.5
Combined Chlorine: 0.0
pH: 7.5
Total Alkalinity: 90
Salt: 2600
Temperature: 83°F

------------------------------------------
Notes 05-28-2019 @ 06:59 AM
------------------------------------------
The second cycle of SWG cancelled because of 6.5 FC. 1230 to 1830.

------------------------------------------
Test Results 05-28-2019 @ 06:31 AM
------------------------------------------
Free Chlorine: 6.5
Combined Chlorine: 0.0
pH: 7.2
Total Alkalinity: 80
CYA: 60
Salt: 3400
Temperature: 80°F

------------------------------------------
Notes 05-27-2019 @ 07:50 PM
------------------------------------------
SWG ran long because of the addition of stabilizer.

------------------------------------------
Chemical Addition 05-27-2019 @ 07:30 PM
------------------------------------------
+ 8 Pounds of DryStabilizer

------------------------------------------
Chemical Addition 05-27-2019 @ 04:57 PM
------------------------------------------
+ 64 FluidOunces of Baume31

------------------------------------------
Test Results 05-27-2019 @ 07:02 AM
------------------------------------------
Free Chlorine: 3.5
Combined Chlorine: 0.0
pH: 7.5
Total Alkalinity: 80
Salt: 3200
Temperature: 81°F

------------------------------------------
Test Results 05-26-2019 @ 08:14 PM
------------------------------------------
Free Chlorine: 3.0
Combined Chlorine: 0.0
pH: 7.8
Total Alkalinity: 90
CYA: 30
Salt: 3200
Temperature: 87°F

------------------------------------------
Maintenance 05-26-2019 @ 08:14 PM
------------------------------------------
Vacuumed, Cleaned Filter, Backwashed, Brushed

The magic salt number is whatever keeps the SWG generating as long as the K-1766 says it is below 4000-4500. The salt level once generating has little effect on the FC output. So move on from focusing on the salt level to why your FC output is not what you expect.

Your signature does not say what cell you have. Share your calculations.

 

[ajw22]

FC of 6.5 does not mean your SWG is generating that amount. Your SWG only needs to generate enough FC to replace CL lost to sanitation and UV during the day. Your pool is not using 3 ppm of CL. That is not unusual.

The calculator gives you a starting point. Then you need to fine tune your % to your pool environment.

 

[scott407]

So if I'm tracking.... I need reduce the runtime for my pump to get in the 3-5 ppm. Does that translate to a 50% reduction in time = 50% reduction in FC (I understand bathing load and sunlight use chlorine at varying rates)

 

[ajw22]

The FC in your pool is either lowering, staying steady, or rising every few days.

If lowering then up your SWG by 10%.

If steady then you have it nailed.

If rising the lower by 10%.

Repeat as necessary. It is a moving target as UV FC loss changes with the seasons.

 

[dradam]

Just to add, I have found that sometimes it takes time for my salt cell to register changes. Sometimes a reboot will do it, but sometimes it just takes time. If your SWCG is happy and making chlorine I would wait a bit before adding more salt. It is much easier to add more than to remove it.