I am looking for high light fixture for a tank that is 12" wide by 12" tall so something that does at least 60 par at the substrate I suppose (give or take since the subtrate is 2").
I am confused with your measurements. there are 3 measurements. Length that is like left to right when looking at it. Then Depth which is like front to back then height which is bottom to top.
The most important to find out if it is big enough is length then height of the tank equats to how bright the light will be at the substrate level.