T5 + MH PAR - T5 has underwhelming levels, does it matter?

[Bpb]

Also, for the record, fluorescent tubes put our more thermal per watt than metal halide and higher wattage levels. The myth of metal halides and heat is just another bad_science myth propagated by reef store clerks making mimimum wage and barely getting their GED. You will raise the ambient temperature of a warehouse faster with 10,000 watts of T5's vs 10,000 watts of halides. T5's can simply hit higher lumen per watt levels at lower wattage levels than halide.

Not sure if this includes induction or cold cathode, but I've never seen those over a reef tank.

Tubes simply distribute that heat over a much larger area than halide bulbs do, so there's the false impression that halides put out more heat.

Without getting too scientific this has been my experience. 2x250 watt mh is actually producing less heat than 8x54 watt sunpower was. Only changing the lights and keeping the same cooling fans dropped my tank temps about 1 degree on average.

 

[Rickyrooz]

I would you the T5's just to give that extra "pop" that the metal halides don't. I ran Phoenix 14K with ATI Blue Plus for years. T5's alone were around 90 PAR but I knew two T5's were just for aesthetics and not the main source of my lighting.