Which T5 should I get

[i have crabs]

Originally Posted by Myka

With your tank being 21" deep you will be limited in what you can keep in your tank if you choose to go with T5s to a certain extent. Once you get past about 14-16" T5s don't compare to metal halide for intensity. You will be able to keep all softies, probably all LPS, and some SPS. If you want to keep certain types of clams, anemones, and SPS corals then metal halide would be a better choice. If you're ok with a few limitations, then the Tek fixture you chose should do quite well for you.

not completly true. going with a 4 bulb t5 id probably agree, 6-8 bulb fixtures have really good par. i have a par meter and have tested lots of lights and my 8 bulb tek fixture puts out better power at 27"down that most 250w halides ive tested by quite alot.

since your tank is 36" and only 21" high id say the a 6 bulb in either the tek or compact usa would allow you to keep almost anything you want, some sps probably would need to be in the upper 12" but most would be fine id think. a 4 bulb might not cut it for sps but lps and softies would be no problem.


im quite shure the compact usa lights with 4 and 6 bulbs have individual reflectors while the 8 bulb and the glo lights have 1 large relfector. you definatly want individual reflectors, imo the glo lights are junk as far as power goes thier cheep so people buy them and will defend them to the grave. i didnt even keep the 2 bulb glo light i bought on my qt tank made me crazy everytime id look at the tank
the 8 bulb compact usa with 1 reflector tested about 40% less power than my tek light with the same bulbs just for a comparison on how much reflectors matter