CFL's and Their Lifespan

change every 6 month br0

Backwoods: here's my two cents worth: That 2700K lamp would be great for flowering but you'd need a lamp in the range of 5,000 to 6,500K's for vegging.
Aerogarden recommends you change their proprietary bulbs every six months and the makers of my two different brands of T-5 fixtures both say to change the lamps every year. Light intensity does degrade over time and starts the moment you first turn it on. In my Aerogardens I change them every six months because the ballast is in the hood and if you cook it you have to change the whole hood. In my T-5's it's every year on New Years Day, just like the smoke alarm batteries. An electrician friend says to also look for graying near the tips of a fluorescent tube or yellowing or browning at the porcelain the base of a curly cue CFL. I hope that helps. HSA