good question...i have the same problem with my fountain. i once bought a product called "no more white scale" at bed bath and beyond ($4.99 for an 8oz bottle) with the good intentions of using it, but that was short lived. my fountain has a float and automatically refills, so i never think off adding this stuff to the water until i am cleaning it out and trying to scrape off the scale.

We got the fountain at Southwest Garden Art in Mesa. I bought their solution to apply to eliminate or retard calcium, but it hasn't helped and I use it religiously. I change the water every two weeks in the summer and once a month in the winter. I am really temped to paint the fount, but would like to know if anyone has this problem and what have they done?

I saw this filter at home depot made for foggers/misting systems that is supposed to filter out calcium deposits. You would probably have to find a way to hook that up or some other filter system or water softener up to your fountain pump. I'm not sure, but just guessing- it would need to be in the line that goes to the fountain pump instead of the line coming out of the pump in order to not affect the pump pressure.. I'm not that technical so perhaps someone else has a thought on that.
If you had a pipeline run out of the water softener (they usually dont plumb them for outside lines due to cost and prob with watering plants but you could have one specially run out) it would probably prevent a lot of the buildup.
As far as the fountain, You could get a concrete stain or even try mosiac tiling that fountain and applying a sealer over that. I am planning to mosiac a fountain with floral patterns as soon as I get all the stuff collected lol.
~SJN

Calcium can be removed by adding vinegar. I use it on my faucets inside the house, on my coffer maker, what ever. So why wouldn't it work in a fountain. If you tile or whatever, it will still get calcium deposits. Give the vinegar a try, see what happens.

I painted my concrete fountain and then put a clear "wet look" sealant on it. It looks great. But guess what... 4 months later same white stains! Going to try CLR and then paint and seal again. Maybe it's an annual event!