THIS IS VERY INTERESTING..THE TEST OF PATIENCE ...the best solution is off-camera multiple flash, and be careful those nasty reflections....polarizer is needed here....let us know the result..gd luck..
1. Setup camera on tripod, as close to glass as possible.
2. Use a off-camera flash cord and mount your flash on top of the tank.
4. Set an aperture like f/8, shutter speed to your flash sync speed.
5. Prefocus on one point where the fish will be coming by.
6. When the fish goes over that point, shoot.
Something like that, which is what I've read previously. Don't havea fish tank, so..... ;p
Originally posted by Flare Well.... I was thinking you can try to switch on the lights of the tank... press the camera to the glass and use flash if necessary... no experience... just what comes to my mind...