T5HO 4' fixture bulb longevity

[naoki]

Katrina (and many others) have lots of nice high light plants grown under T5HO! In addition to the longer day length, if you can put the plants closer to the light source, you get more light, too. But you need to watch out for the heat.

In a long run, HPS (not the older ballast) or high-quality LED is cheaper. For me (100% artificial light), DIY COB-LED with Cree CXA3070 or Bridgelux Vero 29 (which I'm adding Vero 29 to my grow tent pretty soon) is the sweet spot. 3x 50W of COB-LED (about $60 each) easily replace 4x 54W T5HO. Initially, it is a bit more expensive, but it becomes cheaper after 2-3 years (I calculated the pay-back period, but I forgot the exact number).