Photo period length

[Vanquishxxxx]

how long do most people have there metal halides set to run.

[stingythingy45]

I run mine from 2:00 pm till 10:30 pm.

[bexi20]

Two 250w EVC 20k for 8 hours

[thegrun]

7 hours MH, actinics 12 hours, moon lights 2 hours before and two hours after actinics, Refugium light 17 hours (opposite MH schedule).

[DLANDINO]

I only have MH lamps, no supplemental actinic, and run them 7 days per week 4pm-11pm on an SPS dominated reef.

[cody6766]

my 250 burns for about 8-9 hrs

[roblack]

MHs 6pm to 10:20. T5 and led supplement from 12-12 or longer with the leds.

[Vanquishxxxx]

ok so 7-10 hours is a good place to be with MH i run mine for 7 now just wanted to see if people run them for longer or shorter

[DLANDINO]

yes, that is fine but if you are going to extend the time period, make sure you do it over a period of weeks. I would think one hour per day longer per week until you get to 10 would be ok. Watch for sudden algae outbreaks too. If you get one, aside from having nutrient issues, you would want to scale back the photo period until you have it under control. Good luck.

[Vanquishxxxx]

yes i think i am gonna increase the daytime photoperooid to 8 hours. And see at happens i run t 54w t5 for dawn and dusk also so i think a 12 hours cycle total woudl be maybe a little better then an 11 hour

[sohal1025]

8 Hours on mine.