I ran 14w over my old 2.5g w/o issue, so I'm sure you'd be fine. You can also salvage the ballast out of a CFL bulb and drive a PC bulb. Look around for a 18 or 19w CFL (usually 75w equivalent, but they vary), pull the ballast out of the base and wire it into a PC bulb base and voila, you now have a 18w PC bulb and ballast looking for a fixture or canopy. I've posted a few DIY threads on RC and nano reef that you can probably search for. I'm sure a google search on the subject would also give some results. I go tthe idea from someone on nano reef, so i"m sure more than a few have done it.
