There is a very nice fish store in Charleston. It's located on Sam Rittenberg Blvd. I forget the name. The have a great stock of marine livestock. They also have a decent, well kept collection of FW fish and plants. The plants are limited and sell out soon, but if you call them, you can setup a good time/day to maximise ur visit. The best part about this store is very friendly and knowledgeble staff. They are not pushy at all. And yes they have ECOCOMPlete $29.99, if I remember correctly.
I can get you more details, if u r unable to find them on the internet.
Age of aquariums is on Sam Rittenberg. That is by far not the best store in Charleston. No one that I've run across beats Tideline in terms of livestock, drystock, and staff.