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View Full Version : 100w vs 50w LED multichip (for 90 gallon)


jimmy_beaner
08/25/2012, 06:53 AM
I've been reading and reading about the new multichips and I'm still a bit on the fence about the decision between these two. Many of the posts about the 100w chips seem to indicate that unless they're running at ~1/2 power, they melt the tank inhabitants (even SPS). I doubt this is everyone's experience and I'm sure photo-acclimation would certainly help.

I guess my question is based out of whether the 100w or 50w would be good for the tank I'm building. The cost difference isn't much, but if I can only run it at 30-40%, there's not a ton of difference to not go for the 50w. The other option I was thinking is simply to leave off the optics so there's a lot of diffuse 100w light. I did that in my Biocube (I realize it's a far cry from a "deep" tank) and it worked really well. My hope is to run only 2 multichip pendants for the 90. This is another thing that had me leaning to no optics and the 100w chips. I will be building a frame to hold the coolers for the multichips and will be mounting supplemental crees on that frame.

I should also mention I'd be grabbing dimmable drivers and the APEX to allow ramp up and down.

Very open to ideas.

jerpa
08/25/2012, 08:21 AM
Keep in mind that many of the "100w" LED chips can actually be run up to a max of ~250 watts. So if run at "half-power" they may actually be run at about 100w. Ask people for the amperage and forward voltage to figure how many watts they are actually using. Also keep in kind an LED run at half power will last much longer than one run at 75-100%. This is especially relevant in multichips where heat is a major concern and by their very nature you will encounter higher running temps than a 3w design.