Metal Halide Replacement

[reefkeeper55]

Just a question...If I replace all 3 of my 150w 14k metal halides at once how many hours should I run them on/off so I do not "shock " the tank....They are over a 150 gal reef tank ...do not really wish to stagger the replacement so just wondering if I were to run them 4 hours on/off for an entire weekend would this be sufficient...tks

 

[viperbjd]

In my opinion I would stagger them...something like a month apart...to me it's not worth the "shock" risk...

 

[little_fish]

You can start with the lights on for 4 hours a day and increase the photoperiod by a half hour every few days to avoid shock.