MH Lighting Info

[Cap'n]

Just got my first MH light today! Single ended pendant, 175w, just what I wanted. It's used and came with bulbs intended for a FW setup. So I have a few questions:

1) what are the advantages and disadvantages of using bulbs around the 5000k mark? (keep in mind I have a hair algae outbreak at the moment and am currently running NO tubes for lighting)
2) how high should I place the bulb above the water (24" tank, soft corals and zoos only)
3) what type of photoperiod should I use to break the tank in to the new sun? Will I have to do the same when I switch to a 10,000k bulb?

I guess that's all I can think of right now, but please feel free to add any additional info or tips you feel would be beneficial.

Thanks,
Tim

[digitalsteve]

i wanna tag along on this if its ok...

what kind of life can u excpect on a 8 hr photo period out of a 10 k bulb?
175w


do u really need a reflector?

[deacon hemp]

I like to change my 175 MH 10K bulb at around 9 months. and Cpt. i would keep the bulb way high for a week to acclimate your softies,and lower it a little everyday.I also wouldnt use the stock FW bulb it came with,they promote algea as it is.Some ppl like to use window screens in layers to acclimate the new (sun) to there tanks! hope i helped a bit.

Deacon

[ron101]

Lower color temp bulbs usually produce more total light output than higher K versions of the same wattage. Downside is the yellow appearance - this can be controlled by using actinics and keeping water clean.

As for bulb life, I ran my 10,000K Ushios for over 2 years with no apparent loss in coral growth rates.

[StirCrazy]

I recomend going with a 1 hour on one hour off and repete. then every 3 or 4 days add 15 min to the on cycle and minus the 15 min from the off cycle.


Steve

[Doug]

Tim,
Several ways to acclimitize the corals. One like Steve mentioned, is timed periods. I have used his, plus also done a 4hr. on/off cycle. A popular method is to use window screen to block some light. Use several layers, removing one at a time as things progress or even just a single layer, to block some light. I know others , who use pendants, that just raise the lights to start.

I found the 400w version of the Venture 55K, to be a very nice crisp white. Not sure if its made in the 175w version. As mentioned, much more par the lower the colour temp. I currently run two 175w 14K CV bulbs. Nice colour but lacking in intensity. I prefered by pair of Ushio 10K bulbs. IMO< one of the best 175w bulbs out there.

How high its placed, depends on hood height or if pendants are used. You still wish to be high enough to get a good spread but remember every increase in height, takes away from ligh penatration deeper in the tank. The average seems to be around 8 to 10 in. Mine are 6in. but I,m running a pair over a 36in tank.

[Cap'n]

OK, thanks for the great info, folks. I think I'll set it up as is with the low k bulbs for now while the tank and I get used to the new toy. Any tips on where to find a good deal on bulbs?

Also, This is going over a corner tank which is making the whole lighting scheme a pain. I would like to keep my 36" double fixture to add actinics but it blocks a good portion of the tank mounted diagonally. I was thinking maybe a couple smaller single tube fixtures along the straight sides of the triangle instead. Any other suggestions?

[Invigor]

Originally Posted by digitalsteve

do u really need a reflector?

I use flat white paint on the inside of my canopy, and to be honest. my eyes can't notice a difference between reflector or no reflector.. (I have a 12" reflector that's only enough for 1 bulb, and I have 2 bulbs, and standing far back from the tank I don't really notice a difference in intensity... only slight color difference)

the only kind of "benifit" I find is that the lid of my canopy doesn't get as warm with the reflctor..which I guess means either my fans are taking it out or it's being transfered to the water.