<a href=showthread.php?s=&postid=11842843#post11842843 target=_blank>Originally posted</a> by mjstover
Ok. I just got a 24" 96 watt current SunDial. I already had a 150 watt SunPod MH. I was thinking that I might get better results with the T-5s. I just ordered 2 Blue Plus ATI and, a UVI AquaSun. and a UVI 75/25. I was still not totaly convinced that this would put out more light then my MH but everyone is talkin these T-5s up so much I thought I would give em a try. So today I took a Lux meter and tested it out. I put my T-5 on a 16 gal and put the meter at the bottom. on the 10x Lux setting I got about 600 Lum. Then I put the MH on and it blew the T-5s away with 1600 lum. Now If PAR is the most important thing for quality of light how can T-5s come anywhere close the MH?
Couple of issues here. The MH has an extra 54 watts on your 4x24 watt T5 fixture. The Sundial does NOT have individual reflectors - it has a single reflector that is individually contoured around the bulbs. These are not considered to be state of art in terms of T5 reflectors. You're also looking at a single location in the aquarium where the advantage of MH being a point source is going to shine. To do a proper test, you would need to do a grid of readings looking at PAR readings over an area to see how the PAR readings drop off within the aquarium. On a practical note, you would never be able to run an aquarium with the 150 watt MH directly on top since it'd heat up the water like an oven. If you raised the 150 watt MH light to a height for everyday usage, it might be interesting to see how the PAR drops off. The T5 fixture is designed to work on top of the aquarium like you had it placed.
Just some food for thought.