The Proper Technique to Replace your T5 Bulbs We get asked frequently about the best practices for changing out old T5 bulbs, so we wanted to take a quick second to let you know some of our best tips and practices. Changing bulbs on schedule will keep your reef looking great, but follow these tips to make sure you keep your friends in the tank safe as well. - New bulbs typically produce twice as much PAR (output) as old bulbs. To avoid shock to your corals it is always best to spread out a bulb change over a period of several weeks (Reef tank golden rule: nothing good happens fast). - Change out just 1 or 2 bulbs per week. Doing so will allow your corals to more easily acclimate to the new, brighter bulbs. - Brand new lamps have a burn in period of 50 hours. During this time they should not be dimmed; if using a dimmable fixture. They may also illuminate inconsistently or flicker during this period. Don't worry this is perfectly Normal. A lot of people do have questions about the 50 hours of burn in. It is not required to be all at once, and can be spread out over 4-5 days no problem. If you have an active dimmable fixture and you are concerned about keeping the life of the bulb perfect, we recommend the option of a “bulb burn in station”. Just buy a ballast and some end caps and mount them in the garage. Burn a pair of lamps in at a time for 50 hours before use. Keep your bulbs in perfect shape, beautiful and happy corals will come easier! * Please note, many types of corals may not open up as much as before immediately after replacing your bulbs.