Salinity level difference when in low speed pump vs high speed

[Alex1689]

Hope I can find my answer here as i have researched this topic extensively without a successful solution or definitive answer. I have a 1 1/2 hp, 2 speed pump, I ran it last year (i think) at low speed all the time without any issues however I noticed this year that when in low speed 1750 rpm I get a salinity on my controller of 2600 and if i switch to high speed 3500 rpm I get 4100 instead. Was wondering if this is normal as I don’t recall this happening last year and to me honestly doesn't make sense. This is my second year with this system and it seems to be generating chlorine just fine and the flow indicator is good as well. could this be a faulty flow switch, the cell itself or the controller? I m just confused with the difference in salt level and not knowing which one is accurate. I really appreciate any help or expert opinion in this topic.

 

[mknauss]

Welcome to the forum.
Can you tell us what brand/model you have of SWCG? The reading of salinity may or may not be a real piece of data depending on what equipment you have. And we know the actual salinity does not change with flow from the pump.

 

[Alex1689]

This my equipment. Thanks

 

[mknauss]

That is an off brand Hayward Aquarite knockoff.

Can't say I have ever heard of this issue.

Let's tag @mas985 @JamesW @ajw22 for their diagnostic help.

 

[JamesW]

That can happen with the hump up because gasses get trapped in the cell hump, which causes part of the plates to be exposed and dry, which lowers the production.

Try putting the hump down.

 

[Alex1689]

What sensor reads salinity level on these systems? Is it located on the flow switch or cell itself? Maybe I can fix by process of elimination replacing these parts. I know they are cross compatible so that should help. Or I could just leave as is since my pool is crystal clear and my water test readings are within normal parameters. The flow light is good and the system is generating since light is on.

 

[JamesW]

Try putting the hump down.

 

[Alex1689]

Awesome I will try that. I forgot to mention that I just cleaned the cell with muriatic acid hoping that will fix the issue. I will try that and report back. Thanks

 

[Rancho Cost-a-Lotta]

Cleaning a cell with muriatic acid is rarely required. MA can remove the rare metals needed to create chlorine. Take a look at this link and scroll down to cleaning.

SWG How It Works - Further Reading

www.troublefreepool.com

 

[Alex1689]

Wow!!! You guys are truly awesome. That fixed it.
Yeah I had a lot of debris this year and my pool is under a canopy of oaks. Now of course i realize that the correct reading maybe the high salinity 4400 ppm and unfortunately the system high salt level warning light is on.

 

[JamesW]

What are the diagnostic readings?

 

[Alex1689]

Cleaning a cell with muriatic acid is rarely required. MA can remove the rare metals needed to create chlorine. Take a look at this link and scroll down to cleaning.

SWG How It Works - Further Reading

www.troublefreepool.com

Awesome thanks for the advice I didn’t particularly enjoyed manipulating that acid anyways

 

[Alex1689]

What is the best way to lower salinity now that level is high at 4400 PPM? Or is it within the acceptable high end of the spectrum?

What are the diagnostic readings?

I am sorry but this system doesn't have the diagnostics option. I can tell you temp is at 82, salinity indicates between high and lower level light with the reading at 4200 now. Generating light is on and chlorination set at 80%. Flow is normal with no other warnings lights on

 

[Rancho Cost-a-Lotta]

I am sorry but this system doesn't have the diagnostics option.

Double check your manual. Other versions of this unit allow for diagnostics:

"DIAGNOSTIC DISPLAYS Sequential pushes of the small "diagnostic" button next to the LCD display will cause the Aqua Rite to display the following information:"

What is the best way to lower salinity now that level is high at 4400 PPM?

The only way to lower salinity is to exchange water. How are you testing salt levels? TFP recommends the Taylor K-1766 Salt Test Kit.

 

[Alex1689]

Double check your manual. Other versions of this unit allow for diagnostics:

"DIAGNOSTIC DISPLAYS Sequential pushes of the small "diagnostic" button next to the LCD display will cause the Aqua Rite to display the following information:"

The only way to lower salinity is to exchange water. How are you testing salt levels? TFP recommends the Taylor K-1766 Salt Test Kit.

Thanks, i'll try that.

 

[mgtfp]

What sensor reads salinity level on these systems?

I don't think there is a specific salinity sensor in that system. Instead, the performance of the system is used as an indicator for salinity.

The chlorine output is proportional to the current flowing through the cell, so this is the indicator for the controller that the specified amount of chlorine is being produced. At lower salinity, a higher voltage is required to achieve the required current. The system uses this to calculate a salinity value. There is also a temperature dependency which needs to be considered.

If the cell is only partially filled with water, then the cell areas exposed to air are not contributing to chlorine production and are not generating current. The controller doesn't know that the cell is only half filled, and thinks that the increased voltage required to achieve the nominal current is due to reduced salinity.

You can see that this is quite a sketchy way of "measuring" salinity. It assumes that your cell is operating with 100% efficiency. Any performance loss - for example due to scale build-up, or (as in your case) a partially filled cell, or whatever - will be interpreted as a reduction in salinity.

Don't trust the reading. If the salinity reading goes down, then this is just an indication that the performance of the system is reduced. One out of many causes for this could be an actual reduction in salinity.

My SWG for example doesn't even bother to show me a salinity value. It just gives me a low salt warning if it can't reach the required current within the possible voltage range. This tells me that something is wrong and that I should do a salt test as a first action.

Only trust your own testing with the salt drop test mentioned above.

 

[Alex1689]

Very impressed. I am new to the pool world and to the forum and I feel blessed to have at our disposal so much knowledge and experience and also the willingness to share them. Keep up the good work.

 

[Getitrite]

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