Just some information to help you make a decision. My 1.1 ac pond has 7 acs runoff area (not good). It's average depth is 6' and is in the open flat part of SW Louisiana. For 6 years we had no problem with anything, but things are always changing in a pond environment, and we had out die off due to a phytoplankton overbloom due to uncontrollable weather conditions. It never hurts to have a backup aeration system in place. You may not have to run it every year, but you can't to without it when the right,or should I say wrong, conditions occur. Get someone to visually analyse your pond for type and placement of an aeration system. One day you will be glad you did. Losing a pond is like losing your old hunting dog, you can replace him, but it sure hurts for a while! \:\(