I come have come across a article saying no toilet(water) and stair(especially spiral stair) in the middle of the house. It's a piercing sha.
Any master correct me if im wrong.
Maybe u can do a full edit on your house, to check if the fountain is at the right location. ^_^
ExtremeFS has a good point. Fountains in the middle of the house can be difficult. I have a small fountain on the main floor, but it is of a size that can be easily moved. A permanent fountain is another matter.
While a lantern may look nice over the fountain, I don't believe this is good in terms of Feng Shui. This may be a problem you will need to research.
Please let us know what you learn, as this is a new FS problem and we could all use an answer to this.