I discovered a really fun way to make lots of gold, "Booty Grab".
Gaia Aquarium Forums
The forums are full of tanks that are glowing, this gives you the chance to play more often and make loads of money.
Every tank deserves to be played and tapped, but the ones with highr triggers and 17 fish pay the most.
ZOMG was fun and still has some appeal, but if you want cash fast and want alot of it, play "Booty Grab".