Sometimes, telling the difference between hard and soft water in your home is as simple as observing how the water feels. If you're having trouble with hard water, you may wish to invest in a water softener system for your home. You can also use a DIY water hardness test kit or have a water sample taken from your home professionally to test for hard water. There are three levels of hard water — moderately hard, hard, and very hard — beginning with 61 parts per million (ppm) and going up to over 180 parts per million. Soft water includes anything water with 60 or less parts per million.