What Does Dishwasher Salt Do? (and where to put it)

If you own a dishwasher, you’ll be adding dishwasher salt to it on a regular basis as per the manufacturer’s instructions. But have you ever wondered why you have to add dishwasher salt to the dishwasher? If you have asked yourself what does dishwasher salt do? Here’s the answer:

Adding dishwasher salt regularly keeps the water used on your dishes soft

What Does Dishwasher Salt Do?

Many people wonder when using three-in-one tablets in their dishwashers, do they need to add dishwasher salt as well? The answer is yes you do still need to add dishwasher salt especially if you live in a hard water area. 

Dishwashers contain special resin balls which have a negative atomic charge and combined with the dishwasher salt, which has a positive atomic charge, removes the calcium and magnesium which is present naturally in hard water.

When the sodium reserves are depleted in the resin balls, adding dishwasher salt to the machine allows them to absorb more. This is necessary as dishwasher detergents are designed to work better in soft water. 

What Is Dishwasher Salt?

Dishwasher salt is sodium chloride, just like table salt. However, unlike table salt, dishwasher salt is rough, not fine ground and it doesn’t contain any anti-caking agents which would clog the dishwasher.

Never replace dishwasher salt with table salt as this could damage your machine

Dishwasher salt is sold in large rough pieces so that it remains in the salt reservoir for longer and doesn’t all get rinsed away during the first use. Also if you were to use table salt in a fine form, it has the chance to clog up the inside of the dishwasher which would result in your machine breaking down.

There is also the school of thought which advocates using rough sea salt in the dishwasher. This can also be detrimental to your machine as it contains impurities which could damage your dishwasher.

Where To Put Salt In A Dishwasher

Even though all dishwashers are different, the basic design is close enough for us to confidently advise you on where to put the dishwasher salt. The salt reservoir is found inside the dishwasher at the bottom. 

You will see a cap which is often on one side and not central. If your machine doesn’t have a reservoir it might have a built-in water softener (consult your handbook).

Unscrew the cap and you’ll see that it’s full of water. If this is the first time using the dishwasher, the reservoir might be empty, if so fill it to the brim with water. Then pour in the dishwasher salt until it reaches the top of the reservoir. 

Don’t worry about the water spilling from the reservoir, this is normal, and don’t worry that the reservoir appears to be taking so much salt. This is normal and should last for a good few weeks before it needs topping up.

Always use a funnel to fill the salt reservoir and wipe away any salt that accidentally gets spilled into the dishwasher. Take care so that the funnel doesn’t get wet because if it does, the salt won’t be able to flow through it. The salt should never touch your dishes, it is used by the machine to soften the water.

How Much Salt Will My Dishwasher Need?

As there is no standard design for the dishwasher, every make and model has a different size reservoir. This means we cannot tell you how much salt your individual dishwasher needs. Keep pouring the salt into the reservoir until you can see it is full.

This should last for a few weeks before it needs topping up again. You will soon tell when the salt is running low on your dishwasher even without the low salt indicator light being illuminated. If your dishwasher is running low on salt, your dishes will tell you as the glasses will have streaks and not be crystal clear after being washed.

Clean dishes indicate enough dishwasher salt, streaky dishes indicate more salt is needed.

Frequently Asked Questions