ambient lighting

Hey I guys I am new to this forum.. however I have always came here for info on my now 11 year old redfoot tortoise Loki. I live in the Northeast of the US where we have pretty cold winters (can get down to about 10 degrees at lowest) I have a 8 by 4 enclosure (stock tank from tractor supply)...

I noticed recently that the cool end of my tort's enclosure was a little too dark, so I decided to add a fluorescent strip to that side to help with ambient lighting. I happened to have an extra bulb from an aquarium, and I just wanted some opinions on whether it's an ok bulb to use in my...