t5 or MH?

If you put together a good T5 set up, you can have the best of both worlds. A well put together T5 setup will allow you anything with a 90g. IMHO.

 

as soon as I find an extra 2000 grand i'm gonna get some.

 

No not a full led system, it's done just like how moonlights are incorporated into some fixtures. I know there is one company out of Germany that came out with the system in their new units that launched in January (not sure if e are allowed to mention brands).

 

i think a lot of people have a misconception on metal halides over heating our tanks.. Before i go on i want to be clear that i am not saying that metal halides don't massively contribute to heat issues because THEY DO... plain and simple! However, a lot of people think that a metal halide on a smaller tank will obviously heat the water faster than the same sized metal halide would on a larger tank. In fact that is not true! A metal halide is a point source light which means it radiates its light output from a single point. So it is generating a lot of heat in a small area where flourescent lamps may produce the same ammount of heat but it is spread out over the entire length of the tube. Metal halides create more of a heat issue in our aquariums because they heat the air as well as put radiant heat into the water column. So the total exposed surface area of the water will be the key factor in how the lamp will effect the over all temp of the water. So since a smaller tank has less total surface area exposed to that radiant heat in the water column means the less the lamp will contribute to overheating the tank... check out this article Reefkeeping 101 - Ho! Ho! Ho! - Let’s Light 'em Up! by Tom Murphy (aka WaterKeeper) - Reefkeeping.com
He explains it much better than me It is a lengthy article so ill also quote the section that talk about this....

 

Name brands are mentioned all the time. We just don't want to get mean and nasty, bashing companies or individuals and putting Matt in a pretty pickle ITO possible liable claims.

 

I'm still lost on this heat issue...so could it be solved by just adding a fan? What about pendant lights where there isn't any canopy involved?

 

it won't be as necessary because the air won't stagnate and trap heat. but you could still use a clip on fan.

 

Dude I was talking to at the LFS today about MH and heat issues says he doesn't have any problems. Apparently he just suspends them 5-6 inches above the tank, uses an open top, and has a few small fans blowing on them and has no temp issues.

I'm rather concerned about this - I really want to not worry over whether or not I can keep a particular coral. After looking at the 8x54 Tek T5 fixture it would be just as expensive for me to replace the T5 bulbs (replacing 8x54 would be around $160 bucks) as it would be 2 MH bulbs.

 

I'm in the same boat brother.

 

im using the 8 lamp tek light over my 90 and growing SPS at all levels! when i had 2x250W metal halide HQI lamps over my 90 gallon i was always battling the heat. On the other hand...when i had my 36 gallon bowfront setup with a 250W MH HQI the heat was never an issue! So, in contrast to what most people here say...id say on a larger tank go with T5s and go with metal halides on a smaller tank if you are worried about heat being an issue. then also keep in mind that if you are making the price comparison between the tek 8 lamp fixture and a metal halide fixture than you should also work in the cost of a chiller if you go the MH route...