Any autofocus camera will focus on glass that is between you and your subject. That is why you get crappy photos from inside a car without rolling down the window. I have my Kodak at home, so cannot check this out but there is usually a "landscape" mode with a little mountain logo that locks the camera into "infinity focus" mode so that you can shoot through glass...BUT this also means you are out of focus for fish that are close to the camera. You can usually overcome this with cameras that have a manual overide feature for the focus, but the Kodak 4800 does not feature this (can't have everything). I would try using the macro mode which lessens the focal range to between 0.2m and 0.5m, this might get the fish more in focus....OR put the camera in "landscape mode and step back a couple of feet and shoot with full optical zoom. LAST idea would be to just pop the little guys out of the tank for a couple of seconds and catch them flipping around on the floor! Just kidding - don't take offense, but it would work. Good shooting