I just bought some PC lights and they are heating up my tank. I looked and saw that its at least $30 per 4" fan to stick under my hood to help it cool down. I know I can get the fans (ones usually used for computers) for really cheap, like $4. I also think that you could find some AC/DC adapters from some electronic device, like a phone charger or something. Anyone has any experience with DIY fan/hood cooling?