Depends on the size of tank as to what is the most economical way to go.
For a 4' or longer tank, the most economical route is to use T8 shop-lights. that is assuming that you can disassemble the shop lights for parts & use that to build your own canopy. My 4x32W T8 DIY canopy costs maybe $50 in parts.
I am starting to see T5-HO
's in the big box DIY centers, although I have not seen 6700K's. In theory, you can convert a T8 shoplight with electronic ballast into a T5-HO
with the appropriate endcaps. But the main advantage of a T5-HO
setup is the reflectors. You won't get the light output with HD shoplight reflectors, so I don't think it is worthwhile doing this mod.
Another cheap way to get light is to use a glass top (or simply leave the tank open top if you don't have jumpers), and hang lights over the tank from the ceiling. You cna then use whatever fixture you can find at the Hardware store that fits your budget.
Otherwise, look for retrofit kits, either PC
. AH supply's kits (PC
's, link below) are quite reasonable & people have good experiences with them. The T5-HO
kits are a bit more expensive, but is coming down in price & may be preferable to a PC
36 or 55 watt Bright Kits