lights

[Brianwd1]

I am setting up a 178 gallon reef tank. I want to be able to put anything i want to in tank. It is 5 feet wide 2 feet deep and 29 inches tall. Should i go with 3- 250 watt or 2-400 watt metal halides?

[alextheromanian]

most people will tell you 400 that way you can place stuff wherever you want instead of just at the top ( the needy coral anyways)

personally i think...well wonder and i know this isnt a solution but...have you checked out the LED lighting? theres a thread in here on RC where some guy built a KILLER led light system and its about 600$...youll never have to replace bulbs for another 30 years or so lol

[Whys]

High intensity LEDs are enormously expensive. They are more often used as supplemental lighting.

As to the lighting, both options give about the same number of watts per gallon. 3 fixtures might provide more options in placement and bulb types, but either way, if you want to keep SPS, I'd recommend more lighting, like 3x-400w.

JM.02

[Michael]

well another option would be t5s, theres plenty of units available on the market for a 5 ft tank which is 2ft deep, providing its about 6 tubes and has individual reflectors it will do the job, otherwise 2 400 watt halides imo would be fine, you may even find a unit with halides and t5 actinics if you browse the web

[lombard0]

I would suggest 2 x 400W halides with good reflector (wider footprint).

[Brianwd1]

Thanks does anyone know which of the two options would produce less heat 2- 400 watt or 3- 250 watt

[jhoff]

You can also try the new belize sun by Hamilton technology HQI 60" light fixture it's available in 2 150w 250w & 400w double ended HQI & 2 T5 80 w HO actinic blue bulbs & 3 moon lights.Not sure about the heat issue.I would think more watts=more heat.

[der_wille_zur_macht]

<a href=showthread.php?s=&postid=14995443#post14995443 target=_blank>Originally posted</a> by Brianwd1
Thanks does anyone know which of the two options would produce less heat 2- 400 watt or 3- 250 watt

Really pretty hard to answer that question - it's gonna be pretty close. And, IME good ventilation around the lights will cut it down anyways.

I recently had a 5' long tank and used two 400w bulbs above it. The conventional rule of thumb is that you want one bulb for every two feet of tank, but that leaves those of us with five foot long tanks with a recommendation of 2.5 bulbs. It's kinda hard to run half an MH bulb. ;)

With good reflectors, two bulbs will cover the 5' length just fine. And going with 400w bulbs ensures that you'll have plenty of light to spread around.

[andyrm66]

<a href=showthread.php?s=&postid=14995443#post14995443 target=_blank>Originally posted</a> by Brianwd1
Thanks does anyone know which of the two options would produce less heat 2- 400 watt or 3- 250 watt
Its only 50 watts difference, so I would think it would be that much. Have you looked into Tek T5?

[thegrun]

I like the 2-400 watt option because it will give you a wider variety of light and dark areas. True, the 3-150 option will let you keep SPS corals anywhere in the tank with a nice uniform brightness, but I like a little variety in a tanks lighting.

[der_wille_zur_macht]

<a href=showthread.php?s=&postid=14995912#post14995912 target=_blank>Originally posted</a> by thegrun
I like the 2-400 watt option because it will give you a wider variety of light and dark areas. True, the 3-150 option will let you keep SPS corals anywhere in the tank with a nice uniform brightness, but I like a little variety in a tanks lighting.

Two 400w bulbs over a 5' tank doesn't really result in visible light and dark areas, even with poor reflectors (i.e. typical spider reflectors.) It's just so much light that your eyes can't see much of a difference. Though, there will certainly be a little variety in intensity across the tank, allowing for placement of different corals according to their lighting preferences.

Now, try two bulbs over a 6' tank, or one on a 4' tank, and you'll definitely be able to see the gradient.

[Brianwd1]

I have talked to lfs one says go with halides other says tek 5. I still question if 6 or 8 bulbs would be enough light . Plus its cheaper to replace 2 400w then 6 or 8 t5's. I like the shimmer of the halides but am worried about heat since its a built in. I am running a 6 in return from ac unit into canopy area to help.

[KarlBob]

Don't worry, 6 or 8 T5 bulbs with individual reflectors produce a lot of useful light. If shimmer is the deciding factor, check out the LED shimmer modules that have come out in the past year or so.

If you really prefer MH, don't worry about T5. The choice between them is more of a preference issue at this point than a performance issue. Personally, I like T5s.

With a 6" direct return from the A/C unit into the canopy, you should be able to run whatever lights you want, provided that you have a thermostat in the canopy area. If your thermostat is outside the canopy area, the A/C might not notice the localized buildup of heat.

[der_wille_zur_macht]

A tank that large will absorb the heat from two 400w metal halides no problem. I had two over my 5' tank and did not use a chiller. And at any rate, by the time you cram enough T5 over the tank to equal the PAR of two high output 400w MH bulbs, you'll have nearly as much heat in the hood, so it's more or less a moot point.

The choice between them is more of a preference issue at this point than a performance issue.

This bears repeating.

Personally, I like MH. It's simpler (i.e. smaller number of bulbs) and you get that awesome shimmer effect, which - sorry - add-on point source light can't reproduce on a tank lit by T5. Plus, bulb selection is diverse enough that you can get nearly as wide a range of coloration with MH as with mixing bulbs on a T5 rig. However, I respect the benefits of T5 light, and if you want to go that way, it'll certainly be no detriment to your tank.

[WaterKeeper]

I favor the MH when a tank is close to 30". Because they are more condensed in their illumination output, they can penetrate deeper into the tank.

[Brianwd1]

I just finished the return and if i leave the fan set on all the time it draws alot of air. I might burn it up in 2 or 3 years but still cheaper than chiller if it works. I think im going to go with 2 400w just cant decide on a brand? Also cant decide if want to do retrofit or something already togehter with fans.