need help deciding on t5 vs metal halide

[Rouselb]

If you read through all of the posted info, you can see that there are several considerations.
1. Overdriving T5, Standard T5, HQI MH, Electronic ballast MH
2. Combination of lighting based on your personal perception of the tank (MH plus T5, T5 bulb colors)
3. Length of time lights will be on
4. Heating and cooling of the water based on location and room
5. Bulb Life
We are listing all the facts. you need to decide which will work best for your setup.

 

[8BALL_99]

Why would you run T5s and Mh over a 80 gallon? Thats a small tank no reason to use both 2x250 MH and T5s. If you want MH just stick a couple of 14k or 20ks and be done with it. Like others said you really dont have to use 250s. 175 watters would be enough for most things. I would buy the 250s just cause you will probably get a bigger tank sooner or later and you can recycle your lighting that way..

 

[Rouselb]

Like others said you really dont have to use 250s. 175 watters would be enough for most things

250W is needed to obtain decent PAR numbers at a depth of 24". It has nothing to do with the width of the tank.

 

[swpassion]

I might be wrong, but I thought the the higher the k rating (more blue than white) the deeper the light penetrates. So that being said, would'nt 14k or 20k rated bulbs in 175 watt be sufficient vs. 10k? That would also eliminate the need to add actinics.

 

[macreefster]

i have a 70g ( 36"x24"x20"depth) and i run both....but not at the same time. i cut my photoperiod on my two 250w HQI's down to 6 hours so i added 4 t5 HO actinics to run two hours before and after the halides to extend my viewing time of the tank. i sort of like the pre/post halide actinic look, its very tranquil and i love the shimmering, natural daylight effect of the halides. this might be a comprimise that would work well for his 80g.