I know it is not in Culumbus, but these are about a half hour away. I have been to the ones in Columbus, but these are still by far, my favorite.
Seatide Aquarium and Pets-Sell a TON of fish, helpful people, sells plants-Lancaster,OH
R.J.s Aquarium-Lots of fish, and supplies, no plants, helpful and knowledgable people,-Heath/Hebron Ohio.
J.P. Success- Not a whole lot of fish, some supplies/aquariums, not many plants but when they have plants it is a SUPER deal. It is on the same road as Seatide Aquarium and Pets, so might as well check it out.-Lancaster, OH
All stores are Mom and Pop places, and very nice. Hope it helps,