Why that high?

[christa55]

I mounted my aquamedic aquarius 30 light about 4 inches above the water. The light is not that nice anymore in color. My goniopora seems to like it. Before the ligyt was on a glass plate right on top. Why do reef light have to be that High above the water?

 

[edsbeaker]

Here are a couple of reasons, but I’m sure there are a lot more that others will add.

The majority of reef tanks have no lid or have an open mesh lid. Reef lights + saltwater 2” below lights = disaster.

Another reason is that most reef fixtures are made so that the light spreads out of them. A LED fixture might be 7” x 7”, but it is made to be mounted 9” above the tank because it has lenses to allow this very small fixture to spread the light over a 24” x 24” area. If the light was way closer to the water, it would only be capable of lighting a 7” x 7” square.

 

[christa55]

Here are a couple of reasons, but I’m sure there are a lot more that others will add.

The majority of reef tanks have no lid or have an open mesh lid. Reef lights + saltwater 2” below lights = disaster.

Another reason is that most reef fixtures are made so that the light spreads out of them. A LED fixture might be 7” x 7”, but it is made to be mounted 9” above the tank because it has lenses to allow this very small fixture to spread the light over a 24” x 24” area. If the light was way closer to the water, it would only be capable of lighting a 7” x 7” square.

Thank you
My light has no lenses. But your Answer explains a lot