What makes shooting at the aquarium interesting is the difficulty of getting good results. The lighting varies from dim to dimmer, and color fidelity is very difficult since water sucks red out of the spectrum. Additionally the subjects are moving. Tripods aren't permitted.
Unfortunately, the glass / plastic windows compound the problem. The glass was somewhat dirty on the inside (as well as the outside, which is to be expected -- they work at it, but all those sticky little fingers take their toll). Distortion from the thick curved plastic tubes you walk through creates a tendency towards blurred edges and chromatic aberration at the edges as well. The straighter you shoot, the better results; angling downward through the glass invites trouble.
So here's the challenge: you need to get the shutter speed up. This means very wide apertures, which in turn means limited depth of field. Last time I tried this I had a camera that was very noisy over ISO 400. This time I had the Nikon D700 which starts getting noisy over ISO 4000, but is acceptable above that depending on conditions.
So most of the shots in the slideshow were shot at ISO 3500 -4000, f3.5 to 5.6, with white balance varying from settings around 7500 K to auto. No flash. Shutter speeds varied from 1/30 to 1/350. What you really can't do is set-it-and-forget-it because conditions change all the time.
Anyway, I enjoyed the challenge and am pleased with the results, and hope they find a home. Pay the Aquarium a visit and try your hand -- you might get something that thrills you!