[treblig442]

Im thinking about using a rectangle pendant style MH light for a 30g long tank that I am getting ready to set up. Somebody I know has pointed me in this direction, and said a 175w MH bulb about 3-5 inches above the water would be a good lighting source for most corals that I may want in the future. I have NO lighting yet, but need to aquire something relatively soon. I dont want to have to upgrade in 6 months when im actually ready for corals. I want to be able eventually to keep mostly soft corals, but not be limited to Only softies. Any Input? Will that above advice from my informant work out for me?

Thanks for your attention!

[treblig442]

How about using a 250 MH unit found at
250W HL MH Retrofit Kit (HQI) - 25035

with a 40w actinic blue both mounted in the same hood for a 30g long (36")?

[Krazy]

If you plan to retrofit into a canopy a 250MH with some actintc would be nice,
You'd be able to keep just about anything with the 250watt MH !!! (SPS, CLAMS, ETC)

[blind1993]

yea just what krazy k said

[treblig442]

Awesome! Thanks for the confirmation/feedback. I have looked over and thought about so many options. I have really waiting for my mind to come to rest on a final option that i can go ahead and proceed to build. This seems like it might be it!

Thanks again!!!

[pogodzib]

Metal Halides are nice, but they do put off a lot of heat. Make sure you figure out how your going to keep your tank cool before buying your lighting or when setting up your system.

[treblig442]

I plan on having an open top aquarium with no lid. I was hoping that this would be enough to not trap too much heat in. Should I be concerned? Also how what kind of bulb should i use?

10000k, 15000k, 20000k?
If i run one of these with a 40w actinic blue NO bulb which one should I use?

[pogodzib]

Heat is always a concern during the summer months for anyone that uses metal halides. With a 30 gallon tank having such a small water volume, your water may heat up quickly. If you have a sump under your display tank, it would increase your water volume and help your tank dissipate some heat better, so then I wouldn't be as concerned. Also, since a 30long (breeder) tank isn't very tall, you should be able to keep anything under 150w DE or 175w SE bulbs.

Regarding color temp, the higher the k value, the more blue and the slower the growth. 10k bulbs typically have a slight yellow tint to them and have the best par (light strength) output and the 20k bulbs have a very blue color to them (w/ the lowest par output). The 15k bulbs usually lack par and most people don't use them, however there are some good 14k bulbs. With using supplemental lighting for actinics, I like using 10k bulbs, without supplemental lighting, I like the look of 20k bulbs. Color is a matter of personal preference and how much growth you want to sacrifice for the color you want.

Use this link to compare different bulb colors and par output. 250Watt Bulb Comparison

[treblig442]

I am setting up a 20g tank as a sump right next to the display tank. So hopefully between that and having a open hood i shouldnt have too much heat trapped.

[blind1993]

well that is a good idea how big is the sump

[treblig442]

20 gallon sump

[blind1993]

ok well that is good