Bought these 3 small fuschias from Lowes. The guy at Lowes said they would be great plants for a pond garden. He told me to just sit them in the water on the shelf and because they love to be wet, they would grow and flower like crazy. I was so excited, couldn't wait to see the magic. After about 3 days, one bloomed, but then they started to shrivel up and die. Help! I took them out of the water, I've fertilized them with general fertilizer, the dry pellet kind and sprayed them for diseases. How can I save them?

K....are you certain they were fuchias? I have never heard of fuchias being used as a pond plant before! Yes, they like moist soil, but to place them in a pond on a shelf is a certain way of killing them as they are definately NOT pond plants at all.
I would go back to the store and question the salesperson plant knowledge and ask for a refund. Tell him to get some lessons in horticultre also!!!
I would doubt very much if they can be saved as their roots are not designed to be in constant contact with so much water...but you have nothing to lose by trying. Dry them out asap...remove from the pots and wrap in newspaper to absorb excess water, I'd probably cut them back to reduce stress and keep your fingers crossed. Then take a drive back to that store and search out that silly salesperson.
Gill.