Using Water Hardness Test Strips and Drop Kits

Test the water you'll actually pour into the machine. That's the one rule that matters most. De'Longhi tells owners to use the same water you are going to use for your daily coffees.¹

Strips first

Many espresso machines come with a paper strip in the box. If yours does, Breville says to test the water you will be using and then set the level according to the machine's instructions.²

Here's the rough routine De'Longhi describes. Immerse the strip in a glass of water for a second, then check the level.³ The squares change color from green to red, and the result is a level from 1 for soft up to 4 for hard.¹³

That's one maker's strip. Other strips differ in dip time, waiting time and how many squares they have. Always follow the leaflet in your own pack.

Drop kits

A drop kit is a different product from a strip. It comes with its own liquid, its own sample container and a printed card. The method and the unit depend on the product, so this page can't give steps for it.

Follow the card in the box, line by line. The steps that matter are the ones printed by the kit's maker.

Reading the result correctly

• Note the unit. A result in gpg equals approximately 17 mg/L or ppm per grain.⁴
• Write down the date and where the water came from.

If a strip's colors fall between two squares, you can't be sure of the level. The safe course is to follow the instructions packed with your own strip, and to read your machine's manual for what to do next.

Setting the machine

Once you have a level, the next step is entering it into the machine. De'Longhi says the setting up procedure may be different from machine to machine.¹ So read the manual for the exact button sequence for your model. There's a short guide to finding it on this site.

When to test again

Breville says to retest after changing water sources, and then enter the new level on your machine, where applicable.² That covers switching from tap water to filtered or bottled water.

How accurate is it?

A strip gives you a band, not a precise figure. When Penn State talks about buying a softener, it says to have the water tested by an independent lab.⁴ You can borrow the idea if your strip result seems odd.

Compare your strip with the figure from your supplier too. You can look it up from the supplier. Two methods landing in one band? Good. A big gap? Retest. Then read the leaflet again, and check which unit each result uses before you compare them at all.