led advice on 31" tall tank 150g

That looks like a rather tough tank to light well. For high light you're looking at getting a PAR of at least 80 at the substrate but one that also provides a pretty broad area since you do have a wide tank. Due to the width of the tank I would suggest going with two fixtures. 24" is a lot of space to cover and that would mean keeping a very powerful fixture pretty high above the tank. A pair of BuildmyLED fixtures would be amazing and would give you the necessary light but that would also be rather expensive. One option that I've been toying with is a DIY lighting fixture using PAR38 bulbs. It's very easy to build and you can mount the lights wherever needed in order to better cover the entire tank. There are some that are specifically made as "grow" lights that will hit the red side of the spectrum and that would help. Of course there are also your regular white ones that would be mixed in.

Secondary optics will be VERY important. Just to get that light to the bottom. 60 degree lenses on a whole bunch of three and five watt emitters.

Par 38s would be economical. Look at rapids and ecotecs for a more high tek approach.

Algae Beater said:

Secondary optics will be VERY important. Just to get that light to the bottom. 60 degree lenses on a whole bunch of three and five watt emitters.

Par 38s would be economical. Look at rapids and ecotecs for a more high tek approach.

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I agree. One thing I like about buildmyLED is that they give you the PAR data for their fixtures with each of the different optics. It is a great way to visually understand the differences. That is how it is for me at least.

And I do not envy you or anyone you rope into helping you move that pig of a tank.

150 XH tanks are among the heaviest commercially made aquariums in the hobby.

I happen to have a couple of extra par38's from an old reef set up. Would they be of any use or is the temp range too high?
Here is a link to lights I have.
kmas.freeforums.org/full-spectrum-reef-lights-arriving-december-18th-t118.html

I'm thinking those are going to be too far into the blue part of the spectrum. I've been toying with making a fixture with some sort of combination of these two bulbs.

[Edit]
Didn't know we weren't allowed to link to eBay. The first bulb is a grow bulb that has four red 3 watt LEDs (Dark-Red 650~660nm, 620-630nm) and then one blue 3 watt LED (430-440nm, 450-460nm). The other bulb was a simple CREE E27 bulb with five 2 watt LEDs that would be in the 5700K-6500K range.