Yeah, I used macro mode for those. I dropped some shrimp pellets in at the front of the aquarium, and got up close to the glass with the camera. It might help if you use a tripod or something to steady your camera with, when you get in macro or zoom in close the image tends to blur if the camera shakes even a little. I don't have a tripod yet, so I had to take about 40 pictures to get those useable shots.
Oh, also if you're trying to capture moving targets, it helps to change the exposure or ISO speed...faster ISO speed means the shutter closes quicker.