how tall for 250w metal halides?

[yoboyjdizz]

you think 250w metal halides would be enough for an 30'' high tank? i just want to keep a few soft corals and lps... and do you think two in LA3 reflectors would be enough in a 7ft tank or should i just stick with a 6ft tank..i want the focus to be more on the fish...thanks

 

[JmLee]

if your focusing more on fish then you pretty much can go with what ever set up you like. Good luck! =)

 

[yoboyjdizz]

well for the corals i want, i want to make sure they will be able to thrive...

 

[RamPuppy]

I have a 120 gallon cube that is 30" deep.

Stop and think about this for a second. don't "They" say you have to go over 250 watts to keep SPS below 30"?

Ok, so I have 2 inches of sand, now were down to 28" of light I have to penetrate for good growth. I can still keep SPS, LPS pretty much anywhere in the tank and especially up higher in the system.

I have 2 X 250 watt HQI in ReefOptix III pendants driven by icecap ballasts. They are supplimented by 4 26" T-5's that ar actininc and blue plus.

 

[jeffbrig]

If you're worried about being marginal on light, go with double ended 250s. Good DE pendents (ROIII or PFO Mini) put more intensity into the water, but you would need 3 to cover a 6 foot tank. If you're going to go with a broad spread pendent like the lumenarc, you should probably consider 400s. Electrical consumption would be similar to three 250s, but the 400s would be cheaper in initial cost and bulb replacement.

I run three 250w MHs in PFO Mini pendents driven by icecaps, plus four 60" T5s (aquablue and blue) overdriven by icecap 430s. This is on a 72x30x27 tank with the overflow at one end. I'm very happy with my lights.

 

[yoboyjdizz]

my plan was just running two in Limenarc reflectors

 

[yoboyjdizz]

my main concern was electric bill how much more would be two 400's then two 250's? and would two still be ok in a 7ft length

 

[ozfish]

if you just want some corals I would suggest having one or two bommies lit buy MH's and use T5's or VHO's to ligtht the rest of the tank. If you want complete coverage go for 3 lamps in the lumenarcs spread evenly over the 7ft length.

Another Factor that will affect light intensity is water clarity. If you were to skim heavily, utilise ozone and carbon then you could probably keep anything, including SPS and clams under 250's in 30" water. IMO

 

[jeffbrig]

On the surface, that would be 800w vs. 500w (the real numbers vary a bit depending on ballast type), a 300w difference. I'm going to guess in Sacramento you probably pay about 25Ã"šÃ‚¢ per kWh of electricity? So, that extra 300 watts would cost you 7.5Ã"šÃ‚¢ additional per hour they're on. I'll guess 10hrs/day, so that's 75Ã"šÃ‚¢ per day, or $22.50 a month additional. If you're planning to run supplemental lighting and have a shorter MH period, it'll cost less.

Of course, your baseline 500w of lighting running 10 hours per day is going to cost you $37.50 every month.

The important thing to remember is this....unless you're trying to keep acropora or clams on the bottom, you probably don't NEED the strongest lighting available. Plenty of corals will do well with less, and the more demanding ones will do fine if placed in high light areas.

I don't think there's any way 2 bulbs is going to cover 7 feet without dim spots unless they're suspended WAY above the tank. But again, you trade off intensity when you try to spread over a larger area, so its kind of self-defeating.

 

[rjwilson37]

You need 3 lights over a 6 or 7 foot tank, there is not two ways around it, especially a 30" high tank. You can get away using the 250w about 8" from the water, since your only keeping softies and some LPS. I would keep your frogspawn and torches or hammer's and such more directly under where the bulbs are, but can put brains and such in the area's that don't get direct light, because they don't like light as much. Put your Zoanthids and such directly under the light, but other softies like colt corals and kenya trees and mushrooms and such anywhere you want.

If your going with MH only and no supplimental lighting, go with a 12k or 14k bulb, to get good color and growth from your corals.

 

[yoboyjdizz]

yes i was going with the 14k bulb LA3 reflectors cover a 3x3 area so two of them would cover a 6ft area...so why would i need 3?

 

[BadOleRoss]

I have a 30" deep 110 galon tank with 2/250 MH with 14000 bulbs. I am currently keeping several corals and a clam that seem to bedoing well but have only been in the tank a week so who knows. You deffinetly want to use 3 lights for a 6' tank. My tank is 4' long and the 2 lights I have just do the job.

 

[rjwilson37]

I have 2 lights over my 90g which is a 4' tank, 24" high with 2x250w, it is just enough to cover the area. I think a 6' tank with 2 bulbs would be hurting is some area's with a shadow effect. You could always put your lower light corals in these shadow areas and put your higher light corals in the higher lighted areas. I know someone who had a 40g breader, which is basically a 3' tank and these are only like 18" tall. He started with 1 bulb over it and the contrast on the sides was not good at all. So about a month later he purchased a 2nd MH and this was just over a 3' tank and it never looked better.