I don't have my own frag tank, but we've got a couple at the store where I work. We use T5's on those... There's a 60ish gallon with a 4 foot 6 bulb Tek Light, with mainly SPS in it. Our Softie frag tank is about 150g (and twice as tall) with 8 bulbs on it. That tank is five feet long, but we use 4 foot bulbs and just stagger them. Hope this helps you somewhat.