When you’re adding water to your outdoor garden fountain, you might simply use water from the garden hose and think nothing of it. However, if you truly want to keep your fountain in good shape, use distilled water in lieu of tap water.  

Why? Because tap water has minerals in it and over time, it can cause ugly spots and rings in your fountain that are difficult to clean. Distilled water, which is not the same as drinking water or spring water, does not carry the minerals which create the unsightly damage spots.  Once you fill your fountain up, just add a splash of additional distilled water every day to replace the amount lost to evaporation.

And if you live in an especially humid area, you can actually create your own distilled water using a dehumidifier. The collection tank in a dehumidifier can actually collect a few gallons a day in a climate with high humidity, eliminating the need for you to purchase your own.  

Calcium, mineral and hard water deposits can be very challenging to remove once they accumulate so the best advice is to prevent them by using distilled water but if you decide to use tap water you will neet an anti-white scale water treatment, such as dual-action formula of Protec which will provide protection against white calcium mineral buildup, metallic stains and can significantly reduce the need for distilled water. This product will also help prevent pump damage due to hard water buildup