Basically, you take out the flourescent bulb holders and ballast from your old light, and put regular light sockets in, then you can put whatever kind of bulbs you want in there. I spent about $30, and $25 was on bulbs.
When I got my bulbs, I made sure to get the "daylight" bulbs rated at 6500k. I think that they make a big difference compared to bulbs in the "normal" (3000k or so) range.
i want to set up a heavily planted 55 gallon SA community.. i was going to spend the 100 bucks and buy this light,but with both bulbs it only comes to just under 60 watts,dont i want at least 2.5 per gallon??
The coralife fixtures come in saltwater and freshwater. I am assuming you are after freshwater - the link is to the salt version with an actinic bulb. You want the one with the 6700K and 10000K bulbs.
See my thread in this section on thinking of going low tech. Pick your lighting based on what you think you might plant. Most everything I have grows just fine on 1.5-2 w/g.
oh one question.. what is mosr important,higher watts or highers k's?? if i had to sacrifice one,what would it be? cuz if i went with the 41 watt,its only like 2,500 k's... but i could squeeze like 300 watts into my hood lol