Turn off the fountain and unplug any electrical wires.
Remove any stones from the fountain. Use a shop vacuum to remove the water. If the fountain is small enough, dump out the water.
Remove the motor to the fountain. Open the small door on the side of the motor compartment and clean inside the motor with a small brush, calcium lime remover and hard running water. Put the motor aside.
Using calcium lime remover and water, clean all parts of the fountain with a soft sponge. Anywhere the water touches should be thoroughly cleaned.
Rinse the fountain with clean water and wipe the inside with clean, dry towels to remove any leftover cleaner.
Clean any rocks that go in the fountain with calcium lime remover and water. Rinse the cleaner away with water.
Replace the rocks and motor. Fill the fountain with clean water. Plug in the fountain and turn the fountain back on.