Get some helpful tips on taking better photos of aquariums from Nikon, the Nikon Article. The article has some great tips on lighting and camera settings.
Here are a few quick tips to better aquarium photos at home:
1. Clean Your Glass.
2. Turn off your pumps.
3. Use a tripod.
4. Shoot parallel with the glass.
5. Adjust your lighting... blue leds fare very hard to photograph.
#2 is my big no no, I never remember to shut off my pumps except for when I am doing top down pictures and I can tell because I almost always notice particles in the water showing in the pics, as well as a blur even sometimes!