lighting ?

[milesj250]

I am making a top for my 220g reef tank.I am going to use 2 400W and a 175w in the center(up grading to a 250w when $ is better). How much distance to the water surface should the bulb be? The tank is 24" deep.

[mark]

When planning my hood for 250W DE pendants I contacted a couple of companies for height above water. From Hamilton for their Reefstar pendants they recommended 8" above water, from PFO and their mini-pendants they said 5 ".