you have some fast moving fish that's constantly in motion, so I recommend that you keep the flash on. to get good shots with a flash (with minimal glare), you would want very good lighting, possibly adding an extra florescent light strip to the tank.
start off with the automatic setting, and observe the shutter speed and aperture of the camera. it'll change as you move the camera (under automatic), but you get a good sense of what the settings are at once the images are captured.
then you can play around with manual settings using the same shutter speed and aperture as the automatic. once you get the hang of it, you can start to change the settings depending on what kind of effect you wish to achieve with your shot.
good lighting, a stable hand and lots of patience would be critical. I probably take 100 shots before I get a nice assortment of shots that I like and select less than a handful to keep.
start off with the automatic setting, and observe the shutter speed and aperture of the camera. it'll change as you move the camera (under automatic), but you get a good sense of what the settings are at once the images are captured.
then you can play around with manual settings using the same shutter speed and aperture as the automatic. once you get the hang of it, you can start to change the settings depending on what kind of effect you wish to achieve with your shot.
good lighting, a stable hand and lots of patience would be critical. I probably take 100 shots before I get a nice assortment of shots that I like and select less than a handful to keep.
Other than when he's eating.
