To get a new hood I would send an e-mail to Oceanic and ask them. As for the light, fans, etc. They will all last different times. I have had some lights last for a year, some shorter. But you should replace the lights about every 1 1/2 to 2 years. The gas in the bulbs start to go bad, then your just looking at a really pretty light that is still driving you electric bill up, and is doing nothing for your plants. Same thing with the ballast. Ballast might not last to long if they are exposed to the water. Therefore, make sure something is separating them from the water with glass or something.