I thought, by the original post on this thread, that you have hood on the tank now, but are dissatisfied with the quality of the lighting it is giving you.
That's why I mentioned AH. They sell kits that are made to upgrade the hood that you already have by replacing the fixture that is in yours and installing theirs.
What kind of hood/enclosure do you have?
When you increase the lighting of the tank significantly, most aspects of the tank are magnified as well. Everything happens faster.
Plants grow faster, but so does algae. In order to control the algae you have to increase the amount of plants, and get them growing well with fertilization and a carbon source. It becomes more of a challenge to maintain a balance of nutrients/light/plants along with fish. The more light, the bigger the challenge. This is the extra work I was referring to.
Basically, I was giving you a heads up on what to expect with an increase in wattage.
Len