Thanks for the tips!
It is a 10 gallon! It was all I could find in storage. :)
I'd use a compact light fixture if I could, but I currently don't have a place to attach it to/ hang it, and I can't hang it on the tank or it'd brake/fall in the water, and my parents didn't particularly like a wire from the light fixture hanging overhead.
The reason I don't have a proper light is because I used to have this tank outside, with natural sun, but the temperatures started soaring, and that wasn't good. :I
Thanks! I'll try to do my best with getting a new fixture. :)