Originally Posted by TheGrog
They are cheaper because of the bulbs. The ones you get at HD are very yellow in spectrum....and very inexpensive. Bulbs suited for aquarium use are expensive.
Also, the ballasts are usually one with the pendant. This is big and ugly to have hanging over a tank. I have seen them used in coral growout tanks though. Just add the correct wattage bulb of the right spectrum, and it will work. Will be big and ugly, but it will work.
The pendant doesn't bother me, mine will hang over the tank behind the wall, so you can't see it, one great thing about recessed tanks, you don't see any of the ugly equipment, and can use what will work, regardless of how it looks!