Joel Talks - Pool Service Q&A: Salt Water Pool Maintenance

Our Service Manager, Joel Fitzgerald has been with the The Pool Man for 18 years, most of which he spent as our "Boots on the Ground" filling the role of Senior Service Technician.  With over 22 years industry experience, he's seen alot, and been asked a lot...so what better source to answer some FAQs online to help folks out?  This week, we're going to talk about salt water pools, and what to do when your salt cell is in need of service.

Customer Question – “ Why is my salt cell saying I need to add salt?”

#1 Answer – Most salt cells are calibrated in water temperatures above 70 degrees so it is not uncommon when the water temperatures drop into the 60’s to receive this warning. The general rule of thumb is that for every degree below 75, the correction is roughly 150ppm. So if your water is at 65 degrees, the salt reading could be as low as 1500ppm if you are usually at 3000ppm. DO NOT add salt! This is where customers get into trouble. You need to know the true salt reading by either self-testing with a wand or having it professionally tested. Adding salt to a pool that has enough salt already can create other issues that are not fun do deal with.

#2 Answer – Ideal range for salt in a pool is 2800-3400ppm. It is also typical to have a variance of around 500ppm. Most issues associated with salt levels being either too high or too low are well out of this range. Systems that display the salt level are easier to see this issue. For example, if your salt system is telling you that your salt level is too low and displaying 2000ppm but you have it tested and the test shows the level at 2500ppm, this is not an issue, your salt level needs to be raised. If the test shows your salt is 3000ppm and the displayed amount is 1500, this is most likely due to a dirty or faulty salt cell.

Tips/Tricks – Salt cells should be inspected every 3 months for corrosion build-up. Some will have a pre-set timer for this with an “Inspect cell” light. The general rule of thumb for salt cells and salt level issues would be to first clean the cell using a solution (1 part acid to 3 parts water). This is preferred to be done with a salt cell cleaning kit over dunking the cell in a bucket. If the issue persists you can either take the cell to a testing station like Leslie’s or Pinch-a-Penny or call a service company to come out and check it out.

Take-aways - General life expectancy of salt cells is 3-4 years. They can last well over that range but this is dependent on how hard they have been asked to work. Salt cells set at 75% output will not last as long as cells enjoying the sweet life at 45% output. Cyanuric acid levels (CYA)  are very important with salt cells and need to be maintained as the chlorine produced from salt cells is not stabilized and will not last long when the sun is out. Controlling your pH is also just as important. The process of converting salt (NaCl) to chlorine (HClO and NaClO) creates high pH when splitting the salt compound. Adding acid (HCl) to lower your pH will actually reform the salt compound and if done regularly can reduce the mount of salt you need to add to your pool. Maintaining water levels and attending to siphon issues is also paramount. The two biggest destoyers of salt levels are leaks at the equipment or spas draining/siphoning to the pool when the equipment is off. If you have an auto-fill maintaining your pool level, you may not even notice this until you start testing your chemistry. A sure tell-tell sign is your CYA or calcium levels decreasing as these do not evaporate or dissipate. You only lose CYA and calcium through dilution or splash-out.