Can i use bleach in marble fountain to kill algae?

It is not a good idea to use bleach to kill algae in your water fountain. The bleach will corrode the plastic tubing and can damage your fountain pump since it is made mostly of plastic. Bleach can also be harmful to children and wildlife that may be attracted to the fountain. There are several products made specifically for eliminating algae from water fountains and it is best to use these. They are non-toxic and specifically designed to be effective without being harmful or damaging. A great place to find fountain supplies is http://www.thewaterfountainstore.com. Good luck!