huma-huma
Aquarium Advice Addict
id be careful running a 165w LED fixture with 60 degree optics...
the degrees are the focus of the light 60 would be a narrower beam then 90 or 120. 120 would be a wide beam. Wider beams would be used for shallower tanks 90 or 60 would be used for deeper tanks to concentrate the light more. I think most fixtures are of the 90 degree angle.