MH Lighting?

[arc eye]

Hey guys,

I was hoping you could help me finalize my lighting plans.

I am trying to decide between going with one 400w SE MH in a large lumenarc reflector or two 250w SE MHs in lumenarc minis (electronic ballasts on either setup). These would be used on an open top 36x36x18 tank so size is not an issue.

I know you guys have a fair amount of experience with MH lighting and I was wondering you have seen a lot of success with the 250s. I have been reading some mixed reviews. So I am sort of conflicted.

Also, what do you guys have on hand in the way of lumenarc reflectors?

Thanks in advance!

P.S. ............can't wait for the sale!

 

[barrierreefcf]

What kind of reef do you intend to keep? Mostly SPS, mixed, no SPS?

 

[Scooterman]

If your Tank is only 18" Deep, I'd go with the 250W MH & If it was 36" Deep then the 400W MH, simple as that. If you have an open Top & will be hanging the unit, I'd look in to a combo unit that would have maybe T5's, moon lights & built in fans, little pricey but worth it IMO.

 

[mcvicker]

I tried to go with a single 400W metal halide and wouldn't recommend it. Everything does okay but there are shadows and it doesn't look quite right. I would consider either going with the 2 250s or a single 250 in a lumenarc and then t5 supplemental. For an 18" tank I think 400W would be a little bit much.
-chris

 

[barrierreefcf]

Sorry...was out in the field all day and couldn't get in front of a computer 'til now. I'll assume its going to be mostly SPS with some LPS. The 3x3 footprint is a tricky one to light effectively. Supposedly, a regular sized Lumen Arc covers 3x3 but it has too be raised up pretty far. This would require 400w and IMO still isn't ideal for the reasons Chris mentioned. With the Mini's the best you can expect is 2x2 coverage for each if you get them raised up a bit. Depending on how you center them this is still going to leave some lower light strips across the front and/or back. Most of us don't put corals right up against the front so you sould be able to minimize this affect. You could also build an aluminum rack, similar to ours, and add some T-5's to the front and back. As far as wattage...thats a little trickier. Scooterman points out the general rule of thumb but in our experiences its a little more complicated. We run 4x400w in minis over our 96x24x18 and the bottom of the reflectors are 9" off the top of the tank to maximize their coverage. I'm not sure our colors would be as good if they were 250w. We also maintain a 150g bow that uses 3-250w 10k Reeflux with the bulbs only 4" off the top of the tank. The corals grow pretty good and the colors are great. So yes, you can have success with 250w, but IMO the height off the tank, reflector quality, water clarity/quality, and Kelvin/PPFD affect your results more than if you have 400w. In your case, if you use 2x250 Watt I'd go with 10k/12k Reeflux/XM or Ushio 14K in the minis. If you want a more blue look with 20K lights I would use 2x400w Coralvue/Radium/XM in the minis. We all know the downside to 400's...heat/power consumption.

 

[barrierreefcf]

Ah yes...right now we have two regular sized Lumen Arc reflectors which are not set up with A/C kits. We can get any units you need in 3-4 days.

 

[Scooterman]

What K lamps are you using with the 400w lamps?
I did generalize & as mentioned Kelvin used or desired color, height off water & reflector used & corals wanting to keep all plays a big part in a highly productive sps tank. The 250W 10K's I use will outperform most all 400w lamps that use 12,14 or 20K lamps just because of the kelvin lamps use makes that much of a difference, that is why I suggested the combo unit If your hanging you lights as mentioned, the supplemental light would give you more color options without the loss of PAR performance.

 

[barrierreefcf]

We have used 10k reeflux and 12k reeflux in this 400w setup. When we use the 12k's we replace them more frequently. On this particular tank there is no Flo. supplementation of any kind so we gravitate towards the 12k's for overall appearance. If we had extra flo. lights I think we'd go back to 10k for the bump in PPFD, increased growth rates, and longer bulb life.

 

[arc eye]

Thanks Guys,

I was looking at keeping SPS, clams, and a few softies in the darker spots.

I'm was really leaning toward the dual 250w setup for better lighting control and lower energy consumption, but I was worried about them from a coral coloring perspective. I read a bunch of reviews where people were having bleaching/browning issues with their corals under 250w's so it made me gun shy.

Cy, I had no idea your display was MH only it looks amazing!

 

[barrierreefcf]

The display is MH and T5. I was talking about the frag tank behind it