Hours of light

[jjh302]

How many hours of light do fish and corals require? Currently I have my blue t5's come on at 2pm and turn off at 11pm and my two 150w MH's turn on at 3pm and turn off at 10pm. Do they need longer?

[Rutrag]

Intensity is more important than duration in most cases. I know of some coral farmers who run lights for as short as 8 hours a day total. I run mine for about 10.

[jjh302]

I run a 36 inch fixture that has 2 t5's and two 150w MH's. Last night I changed the t5's and upgraded to the Red Sea 440nm bulbs. I need to replace the MH's bulbs next. It currently has the 20,000k bulbs in it. Should I stick with that or should I go to a 14,000k bulb?

[Rutrag]

It depends on how blue you want the tank to be. The higher the Kelvin rating, the more blue things tend to look. I personally like the 14K bulbs.

[jjh302]

If I change to the 14k will it take away from the flouresence of my corals?