On such a small system, the overflow to the sump would assist with pulling the warmest layer of water off the surface, specially important if you select a MH fixture (also removes the unsightly layer of surface film). It would also assist in cooling to a degree while the water travels to the sump. More water also helps.

I foot long pendant would cover 24"s nicely, put may produce a spotlight effect if placed to close to the water. This is by all means possible, expect lover light areas on the sides of the tanks.

The difference between compact florescents and HO T5 is shocking. A 24" HO T5 fixture would cover the tank nicely (both front to back and side to side) and would likely add less heat to the system. Go to a LFS and check them out if you can. I would never give up my 400W halides, but since I own a HO 8 bulb T5 unit (over my grow-out tank), well IMO it is worth considering.

for your tank's dimensions I think T5 would give better lighting than MH will. And the PFO pendant is a little too focused to cover your tank across the full 30 inches. A 24" tek light or the likes (make sure it's HO and individual reflectors) would outperform a MH, especially watt for watt.

sanjay has data on the PFO reflectors and the spread's too narrow for the entire width of your tank, and overkill if you were using 2.

now as for something you can reuse on a larger tank, a sunlight supply lumenmax 3 might be a good choice. It'll do a better job than the PFO of covering your 30" wide tank, and when you upgrade the tank, you just add more lumenmax's. The lumenmax is for a 2'x2' area but you might be able to stretch it enough for your tank. You'll have some light over-reach front-back I'm assuming.

Thanks for all of your input guys. I did some thinking on the wattage, heat etc and my focus as turned to this item I found at J&L

Coralife AquaLight Pro Metal Halide HQI Clamp-On Pendant - 1 x 150W

It's height is somewhat adjustable, clamps on easy and you can add more if you chose. i could buy 3 of these bad boys for the price of a 250w MH & PC canopy by Hamilton or PFO.

One more question remains though.. Is the intensity and effectiveness of multiple lamps be different (better/not better) than one big lamp?

I have seen these in action at the LFS. Not sure I would recommend them...this light is very small, maybe only 8" across and would really only act as a spotlight on a 30" tank. Would be good for a refugium that required metal halide. Have you considered this one?

http://www.jlaquatics.com/product/sl...C+4+x+24W.html

If this is not for you, I would consider trying to gind a single 250W or 400W pendant used - they are often at least 4-8 inches wider and would provide you much better coverage.

What are you planning for actinics if you go with a single pendant? Gotta love the actincs.

Alright wickedfrags, I think you sold me. 96 watts just didn't seem like much light but from what I have been reading, the efficiency and "PAR" makes a light. I might go with the 36" one instead though

http://www.jlaquatics.com/product/sl...C+4+x+39W.html

It will add a little extra power and leave overhang so I can rest it across my tank rim, and do away with the cheap plastic canopy 65w pc is on. I will have to see when I go to J&L on Saturday.


What kind of SPS do you think this will support? Monti etc?