What is a ballast for? Difference between these two cool tubes?

This one includes a ballast and is tube shaped:$145
http://www.amazon.com/gp/product/B004HNPGKA/ref=ox_sc_act_title_1?ie=UTF8&m=A325274ZEF9XYZ

This one doesnt have a ballast, looks like it reflects more light and is $99
http://www.amazon.com/LED-Wholesalers-GYO2501-Hydroponic-Reflector/dp/B0043CQQTA/ref=sr_1_3?ie=UTF8&qid=1319068483&sr=8-3


I just have a small grow tent: 36"x20"x5'. Which one would suit my needs?

the ballast is the power supply for the light. Go for the first one.

The first one is a complete light set up, the second one is just a reflector/hood..........no light.

Jack Harer said:

The first one is a complete light set up, the second one is just a reflector/hood..........no light.

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Thanks. If I bought a bulb it wouldnt just work with the second one? I'd still need to buy the power supply too?

I guess Im just confused as to why one has a power supply and the other seems to just plug right into the wall.

No, HID lighting requires a ballast for the bulb to work.

the reflecter actually plugs into the ballast and the ballast goes into the wall. Even CFLs and fluros have ballasts. I'm not really sure why they need one, but I assume its because they need to convert the power into something else. Like AC to DC or something.

Jack Harer said:

No, HID lighting requires a ballast for the bulb to work.

Click to expand...

Ah I see now, thanks bro