Hi I am an owner of redtails (RTC's) I was wondering, when the lights are off could I use flash on my camera to get a much better picture? Please help guys thanks.
I think the picture pros use a remote control flash from on top of the tank to get the beautiful shots with a black background.
This.
If you really want good quality aquarium photos, you're going to need either a) very strong tank lighting, b) A camera with a flash hotshoe, a set of radio flash triggers, and a flash unit/speedlight (this is the type of rig I used when I took my avatar picture; I used a $20 trigger set from Cowboy Studios with my Nikon D3000 and Nikon SB-600 speedlight), or c) A camera with a built-in system for wireless flash, and a compatible speedlight.