Aquatic Life Light T5 HO 4-Lamp 2-Lunar Aquarium Light, 30-Inch - NEED HELP

[Old Scales]

Anybody have this or know this light? I ordered this and will get it Wednesday. My curiosity about something on it is killing me. LOL
It has three indicator lights on its program window. One is LED(for the night LEDs), one is T5(showing the main bulbs) but one says HID.
What is the HID indicator light for? Thanks, OS.

 

[aqua_chem]

HID usually refers to Metal Halide lights. Many fixture use T5HO and MH combined. It's possible that the fixture shares the same front panel as one of those fixtures.

 

[Old Scales]

OK, thank you. OS.