I've got a two year old we call Airborne. Not just because I was in the 101st, but because he's absolutely deserving of the name... as well as Crash, and Godzilla. We have handle-less cabinets and just used those cabinent baby proofing kits from Home Depot. We also built a fake and ghettoish top, sort of, a open canopy that is just three sides of wood resting on the aquarium to keep the kid from being blinded by the pendant light. And I NEVER leave chairs near the aquarium. He's been told since he was born to not touch the aquarium or bump the stand, and whenever a ball or truck rolls into the stand, the whole house chimes in with UH-OH!!! and we send the offending toy off in a new direction. Twice I've put his TOYS on time out for hitting the fish stand. "Your mean old truck ran into the fish, that was BAD. The truck is going on TIME OUT. He has to stay there until the fish aren't afraid anymore."
End result... the fish are safe, but it takes a razor blade to scrape the tortilla chips and kid spit off the TV. Shows where OUR household's priorities lie.
Oh, and the kid already knows how to say HI Evil Blenny!
Good luck!