Metal Halide: Osram Daylight vs. Osram Cool Daylight

[Stamboli]

Hi!

For my upcoming Shallow Reef (50 gallons) I will use two 70 Watt Metal Halide bulbs from Osram. Two models are possible: Osram Excellence Daylight with 5200 Kelvin and Osram Excellence Cool Daylight with 6500 Kelvin. The difference between these two bulbs is probably not very big, but I want to choose the better one. Based on the spectrum, which bulb would you choose?

Left side: Daylight 5200 K / Right side: Cool Daylight 6500 K

 

[X-37B]

Hi!

For my upcoming Shallow Reef (50 gallons) I will use two 70 Watt Metal Halide bulbs from Osram. Two models are possible: Osram Excellence Daylight with 5200 Kelvin and Osram Excellence Cool Daylight with 6500 Kelvin. The difference between these two bulbs is probably not very big, but I want to choose the better one. Based on the spectrum, which bulb would you choose?

Left side: Daylight 5200 K / Right side: Cool Daylight 6500 K

6500k

 

[CBonito]

Agreed on 6500k.

 

[Troylee]

6500k grows corals extremely well, but they will be brown! Very brown lol..

 

[Stamboli]

6500k grows corals extremely well, but they will be brown! Very brown lol..

Depends on the corals. Fluorescent corals, you are right. In terms of vibrant corals / colors it's different.