So I'm going to be getting a 56 columnar tank (30"x18"x24") and moving into the medium light range. I understand that a single fixture will not provide adequate coverage on an 18" deep tank and the plan is to get a Finnex 24/7 running the pre-programmed day cycle and dose Excel but I'm going to need another fixture for up front coverage. I'm considering getting two 24/7s but the question is what the beam angle is on these fixtures and if I should just run a Stingray up front instead rather than risk having high light where they overlap. If they are six inches apart atop the tank then wouldn't I be getting around 80 where they overlap? Would spacing them as far apart as possible do the trick with the front fixture towards the front edge of the tank?