will this light be good?

okay there are 2 types of canopys
1- Glass - consists of 2 pieces held together by a plastic hinge. The light you are looking at can be placed on top of this glass without a problem.
2- Box - A box canopy that goes on top of the tank, usually used for diy purposes to install own lighting. The light you are looking at would not need this box canopy.

Also before you actually go with that light look around there are a few places that sell that light for cheaper and there are other lights on the market which can provide the same amount of light and be easy on your pocket.
 
depending on your type of tank (either aga/perfecto) you will need the different type of glass.

Heres that same light cheaper. Plus order around friday-sunday and get $5 off.

But if you dont want to switch out the bulbs later on (since they do cost $15-25) you can get this unit. (but this is only if you will be doing plants in the 29g you are building)
 
This is what comes with the glass canopy you are ordering (but it wont be 6')
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