LED and PAR38 Lighting

[Sidekick41]

Hey everyone,

I've been trying to research lighting as I know I need to upgrade my 4 bulb T5 lighting for my 55 gallon. I have seen on several site, people talk about 30, 60, 90 degreee lighting or optic. Can anyone easily explain this? Not sure what effect it has and which I need.

Thanks in advance.

 

[RockStacker]

Lower angle optics will focus more light in a narrower cone.
So they will provide stronger light, but will cover less area.

Higher angle optics will be the opposite. They spread light in a wide cone, but the illuminance will be degraded as it is spread out farther.

Imagine the adjustable cone nozzle of a garden hose. The narrow cone produces a stronger stream but with less coverage.

So in terms of practical application, here are some scenarios:
For deeper tanks or tanks with corals that require very bright lights, you might need more LEDs with narrower optics to provide the necessary PAR to the corals.

For shallow tanks or tanks with corals that do not need a lot of light, you can use less LEDs but with wider optics to spread out the light more.

 

[Aquarian]

+1 Rockstacker. Well said