Your family uses a lot of water! Between normal everyday use, the swimming pool, and friends coming over, that’s a lot of water that needs to be treated. You have a water softener that uses salt and so does your swimming pool. Is the salt the same for both?
While the quality of swimming pool salt is as pure if not purer than most water softener salt, the size of the grains can make it not ideal for a water softener. The fine grain pool salt can encourage bridging and not allow the brine to draw into the water softener quickly enough to be effective.
I know that by looking at swimming pool salt and water softener solar salt, there is not much difference. But there is enough of a difference in the coarseness of the salt to make a big difference in how it will work in a water softener.
What would happen if you used pool salt in your water softener?
The fine pool salt does not allow water to flow through it quickly enough.
If you were to put swimming pool salt into your water softeners salt tank, it would be like putting a very dense water filter where a very non-dense water filter should be.
The reason that this can be a bad thing is that when the water softener draws the brine (saltwater) from the salt tank, it gets slightly diluted by the freshwater that carries it along and if the brine does not draw out of the tank quick enough, the brine can get diluted to the point where it is no longer as effective as it should be.
This densely packed salt causing slow drawing of the brine can also mean that the brine may be drawn right to the very end of the regeneration process, and that can cause your water to taste salty.
Normally, the brine is drawn out of the brine tank quickly, it is then drawn through the water softener resin and then rinsed away by freshwater once the brine is emptied from the tank.
If the brine is drawn too slowly, the freshwater may still be drawing brine from the tank when there should be no brine left. And therefore the salty brine will remain in the water softener tank which will then come out of your faucet.
The tiny particles of pool salt can clog your water softener valve.
When the salt sits in the water inside of the brine tank it becomes slightly smaller because some of it dissolves into the water.
When you have many larger sized salt crystals, they will shrink at different rates so not all of them will become so tiny that they will be drawn into the water softener control valve.
But when all of the salt crystals start off as small crystals, you will have most of the salt crystals flowing through the water softener valve, and this is when they can build-up and cause problems.
This is not common but when it happens, it can turn out to be an expensive repair bill and in some cases, it could mean replacement of the entire valve.
So, can you use water softener salt in your pool?
Providing that the water softener salt is very pure and free of debris or additives, you can use some types of water softener salt for your swimming pool.
Water softener salt that says “Solar” or “Pellets” on the bag are very pure salt and will work fine for swimming pool use.
Avoid salt that says “Crystals” as they may have dirt mixed in with the salt which will end up in your swimming pool.
There is no need to use water softener salt that has any additives in it if you are going to use it in your swimming pool.
I recommend using salt that is designed to be used for swimming pools but if you have to use water softener salt in a pinch, stick to the salt that is in a blue or blue/white bag from a well know manufacturer because it should be pure salt with no additives.
I accidentally bought pool salt for my water softener, should I bring it back?
If you have already added a bag or two of swimming pool salt to your water softener, it will not likely cause any harm to the system but you may experience some salty-tasting water after the water softener regenerates.
I would leave the salt in the tank and wait until the salt level gets down to about 1/3 of a tank, then add 1 bag of water softener salt. Then wait until the salt level gets down to 1/3 tank again before adding more salt.
This should use up the swimming pool salt and safely get you back to using water softener salt. If you have completely filled your tank with swimming pool salt, I would scoop out most of it and put it aside to use if you run out of water softener salt.
Return any unused bags or swimming pool salt to the store that you purchased them from. This has very likely happened before, and the store should take them back without any problems.
