t5 vs MH

i had a 150 on my 31G and i had loads of problems. Did you use a chiller? I never, maybe that was what was wrong...

 

wow, maybe im crazy but i have a 250w over my 20 gallon. been on there for over a year and ive never had a problem.

 

I have 250's over my 90.... And YES HEAT IS AN ISSUE.

 

Just changed over to T5...and MH was certainly hotter than the T5...just by virture of the element....without getting to scientific...that is a fact....now in my case with a 55 and a 90...It really was not significant...But MH was hotter.....JMO
This debate will go on as long as we are playing with these thangs !! Now is'nt that the way it should be?..... and the debates continues....BRAVO !!
LG

 

I completely agree with OP on this one, the shimmer effect is awesome.

 

One of the main questions from the OP is "are there corals that HAVE to have MH lighting?" It depends on your scenario. Dr. Frag would tell you "no." He's a huge T5 fan. If you would eventually have a tank dominated with SPS corals, T5's might not be the best option if your tank is deep. I don't know the depth of your tank. Halides are without peer in the amount of light they throw off. T5's are without peer in the light/heat/cost ratio. It's not an easy decision.

There are many variables that contribute to the heat issue. Missionsix ran dual 250's over a 55 gallon tank without a chiller. I have dual 250s over my 90 and I must run a chiller. It's an equasion dependent upon ambient room temperatures, distance of lights to water, wattage of lights, evaporation rates, water flow, whether or not a sump is involved, and probably some other variables.

I've seen a few nano's that come with a MH pendant light, but the light is a good 10" off the water. In this case, heat probably wouldn't be an issue.

As seabass1 says, T5's have depth limitations.

Everyone makes valid points on this thread, and as much as we'd like to think such might be the case, there is NO correct answer to this question. If you utilize a MH pendant over your 29 gallon tank, you're going to have to use a specific type of pendant, lest your light get wasted and thrown all about the room.

If it were me, I'd go halide, but I'm a halide fan.

Good luck making your choice. The more questions you ask, and the more reading you do, the better your outcome and ultimate decision.

 

I never ran a chiller, i had the lights 8 inches above the water with a fan blowing across the top

 

I am surprised that Doc Frag has not chimed in on this.

I can say that even on 2 foot tall tanks that a proper t5ho setup, not even an Overdriven one can easily make a lot of PAr, even on the sandbed.

Doc frag's 180g lit by 8 I think 60" normally driven 80w t5ho retrofit bulbs has at least 200 if not 250 par on the sand bed. This is a shallow sand bed on a 24' tall tank, and to be fair, he is using workhorse ballasts. These ballasts don't quite make as much PAR as a t5ho specific ballast.


I had a 3 foot long 35g that was lit only by 3x39w of t5ho retrofit on a workhorse 5 ballast. I would fry many LPS even at the bottom of the tank that was like 17" tall.

 

I have 2 250's over my 75 with no heat issues. They're fairly close to the surface as well, maybe 5 inches. I also know people with 150 watt vipers over their 29 cubes. No heat issues.

 

My tank is only 14" deep so if I went with the t5s them I'm guessing there wouldn't be a problem with penetration to the sand bed. Besides, I don't want to go out and get a MH lamp and then turn around and have to get a chiller also. I'm currently in college so money is always an issue right now. I've found the following fixture so tell me what you guys think of it:

T5 HO LIGHT REEF HOOD 6X24W 60cm T5HO LIGHTING FIXTURE - eBay (item 160359660680 end time Sep-11-09 01:48:59 PDT)

Also, if anybody knows of a way to modify the original biocube hood for t5s, could you please let me know. I like the look of the hood, so if i could keep it that would be great but if it has to go, it has to go.