Salt Water Generator Defective

[Homewatcher]

Hi, I have an Intellichlor SWG that consistently will indicate that salt levels are good even when test strips yield 1680 ppm salt. Upon inpsection there is no scaling inside the cell and the plates are all clean. Eventually, the cell will indicate a low salt condition. I'm thinking that the cell may have reached its end of life, although when I tested the pool with this salt cell, I was reading 8 ppm Free Chlorine even with the 1680 salt level. Obviously, the cell is putting out chlorine even with the low salt levels in the water. Does anyone have any idea as to what may be going on with this system?

Thanks

 

[JasonLion]

Most likely your test strips are just completely wrong. There is no way the SWG would work at all if the salt level was 1680.

Intex SWG cells tend to need to be cleaned regularly. A dirty cell behaves much like a worn out cell, except it gets better when you clean it out. There are instructions on cleaning the cell in the manual.

 

[ping]

It sounds like your test strips are not reading accurately due to either bad strips or testing error.

If the SWG is happy and making chlorine don't worry about what the test strips are reading, what is important is what the SWG says. When cells start to go bad, they will start reading a lower salt level and that is when accurate testing is needed to diagnose what is wrong.

 

[Homewatcher]

Test strips are brand new and were purchased from TFTestkits along with the TF100 kit a week or so ago. I also took a water sample to the local pool chemical store to see what reading they got on the salt and they came in at 1850 ppm so really close to my numbers. We pulled the SWG and inspected the interior and the cells were completely clean. I didn't think this unit could produce salt with this low of readings so something is definitely strange. So should I use a different testing protocol now to measure the salt in the pool water to determine if the cell is indeed bad?

 

[RobbieH]

I have a lot better luck with the drop based test kit than the strips.

 

[Homewatcher]

I have a lot better luck with the drop based test kit than the strips.

I asked the pool chemical store if she used test strips or drop based. She advised that she did it both ways and came up with almost the same number of 1840 to 1850 ppm of salt. This pool is being maintained by an outside service so now I'm suspecting that something is being done with manual introduction of chemicals. When I tested yesterday, I had FC = 8.5 and CC = .5 and PH = 8.2. When I rechecked it today, the FC = 3.0, CC = .5 and PH = 7.4. There has been no bather load and pool has remained covered overnight between these tests. My best guess is that someone came in and re-dosed the pool with various chemicals to drive down the high chlorine levels and the PH levels. There are no log sheets from the outside service to indicate when they showed up and what they did. I seriously doubt the pool corrected itself in 24 hours without someone introducing something. Would this be a safe assumption?

 

[jblizzle]

No way the pH dropped without acid addition.
The FC drop could just be due to the sun and organics in the pool.

 

[ping]

Bump up the salt level to recommended levels of the SWG and see if it starts working correctly. It sounds like the strips and other tests do match reasonably well and I would go by those readings. I thought that you had 8 ppm of FC that was generated from the SWG, but with this other information it seems highly unlikely that the SWG was producing chlorine.

 

[Homewatcher]

Bump up the salt level to recommended levels of the SWG and see if it starts working correctly. It sounds like the strips and other tests do match reasonably well and I would go by those readings. I thought that you had 8 ppm of FC that was generated from the SWG, but with this other information it seems highly unlikely that the SWG was producing chlorine.

I think you are right. The pool service probably has been manually adding chlorine instead of correcting the low salt concentrations to allow the SWG to correctly produce chlorine. Based upon what all of you have said and the other research I've done, there is no way for this salt cell to be producing an FC = 8 ppm with these low salt concentrations. I've directed the pool service to monitor and maintain salt concentrations so that the SWG will function correctly. We also did a calculation of the LSI and came up with an index of -0.6 which indicates corrosive water so there are obviously other problems with alkalinity, calcium hardness, PH, TDS etc.