As a side note the display on the Hayward control board was at 3400 tonight even though Taylor was at 2800. Should I trust the Hayward readout over the Taylor kit? Thanks
From my own experience, there are a couple things that can affect the SWG salt readings.
First, the Hayward SWG, like many other SWGs, measure salt level like a TDS meter does. It uses the voltage, current and water temperature to calculate conductivity and convert that into a salt level. One of the issues with a TDS measurement is that it includes ALL dissolved solids and not just salt (NaCl). Some of these other dissolved solids (e.g. calcium, magnesium, potassium, etc.) are also conductive so the salt level reading will typically read a little higher than actual depending on the level of these other solids. As the cell ages and the plates become damaged, it will start to read lower and lower "salt" until the cell completely fails.
Second, what I have found is that when the pump first turns on, the cell thermometer could be reading a temperature that is closer to air temperature rather than water temperature because it takes some time for the cell housing and thermometer to adjust to the temperature change. The SWG controller takes a salt reading fairly quickly after starting so if the salt cell thermometer is reading lower temperature than the actual water temperature, the calculated salt level will be higher than actual. This then is average into the average salt reading which is displayed by the controller.
However, after 10 min or so, if you look at the instantaneous salt level in the diagnostics menu, you will probably find that it is now closer to actual salt levels.
