Water questions. I am confused as to what I can use for hard & soft water. Is purified bottled water considered soft water and is tap water considered hard water? Any examples of hard & soft water?? Thank You.

Hard water is water that contains dissolved limestone. If your water comes from an area with limestone (or you can prepare your own adding some calcium carbonate and removing the undissolved part) then you have hard water.

Purified water, yes. As long as there are no metal cations in this it's called soft.

You might want to check this article on wikipedia:
Hard water - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Hard_water#Softening)

Distilled water would be the ultimate in softness; your tap water will depend on where you live/your tap water source. Try contacting a local water softening company and see if they could help you. They may have a source of standard hard water you could use in your tests.

I live in Delano, California. Maybe that will help to see if you can tell if we have hard water here. Also can you give me examples of hard water?

Can I make my own hard water by adding epsom salts to regular tap water?

I would guess so. I can't give a definite answer because I don't know the composition of hard water where you live. If you can contact your water softening company like Dr.Bob suggested, you'd have a better idea and you'll maybe even get advice on what you can do to prepare your own hard water which will be more realistic and hence more practical for your project.

I wouldn't say that there are 'examples' of hard water. I would say more in the sense that there are different extent of hardness of water, of course, depending on the concentration of the ions in it.