Switching to Metal Halide

[cmiles]

I am finally making the switch to metal halide on my reef tank. 2x175 watt, 2x96 watt pc, and 4 moonlights. My question is how will this affect my reef, will I have to cahnge my lighting schedule at first, or will I have to move everything to the bottom. I dont want to fry anything. I am changing from 260 watt pcs on a 55 gallon. What should I do??? :help: :help:

 

[nm reef]

I would gradually bring the MH's on-line. Basically keep the same light schedule but add the MH's for a few hours at first then icrease the time they are on weekly until you get the photo period you desire. For example if you now run your lights for 10 hours per day say from 10am thru 8pm then keep that light schedule and add the MH's maybe from noon until 4pm...then each week increase the time period for the MH's.....make sense?

 

[cmiles]

So basically I run from 9 to 9 so I would need to run the 2x 96 watt pcs for the regular schedule and the mh from maybe 12 to 6 and then increase the mh every week by maybe an hour??? How many hours total eventually would be okay for the mh, should I eventually work up to the 12 hours a day like with the pcs or go for 10 hours with the mh??? Sorry so many questions, just so nervous about changing, scared to mess anything up the tank is doing great. I just have a couple of clams and felt the need after researching to change to better lights.
Thanks

 

[cmiles]

Also what is the difference in external and internal ballasts???

 

[seareef]

Originally Posted by NM reef
I would gradually bring the MH's on-line. Basically keep the same light schedule but add the MH's for a few hours at first then icrease the time they are on weekly until you get the photo period you desire. For example if you now run your lights for 10 hours per day say from 10am thru 8pm then keep that light schedule and add the MH's maybe from noon until 4pm...then each week increase the time period for the MH's.....make sense?

Completely agree'd if you add them to fast it will burn the corals. Kinda like your skin in the sun, if you start tanning for 10hrs at a time...you'll fry your skin, but if you work up to it...you'll be fine outside all day with no problem.
Anywho... another good pattern is to:
Take screen (kind you would use on a window or door) and layer it...4 or 5 deep so light can get through...but not in a massive pattern...
anyways cut it to the shape of your tank...and then make it so it stays some way or another... i would glue it to wood...that would normally hold it....
and over time (week by week) remove one layer...increasing the light so the corals can slowly adjust.
WORKS WONDERS.
good luck!

 

[cmiles]

Thanks that sounds simple enough. I think I will keep the pcs on normal schedule and run the halides 3 hours and increase one hour per week until I reach maybe 10 hour periods with them. I think the pcs are actinics though will that matter???? Also I have a canopy so I will probably have to set the lights on the top of the tank like I do my pcs. I just have 2 boards one on each end holding the fixture on the aquarium. Probably 2 to 3 inches from the water. Do you think this may be a problem?? I have always run a fan into the back of the canopy to keep the pc's as cool as possible, do you think if I continue to run the fan in the back of the halides this will help???

 

[wangotango]

wait. are your lights gonna be 2-3 inches off the water? if so that might cause a problem, and you're going to need more than just one fan with halides under a canopy.