Smaller fish stores and pet departments in department stores often do not carry marine aquarium supplies. You can get them at most larger dealers as well as online here:

• Salty Supply
• Boston Aquafarms
• Golden-ina
• Marine Depot
• Red Sea Fish
• AquaCraft
• AquaVitro
• Coast Tropicals
• Exotic Reef Imports
• Fish Heads Inc.
• Premium Aquatics
• Reef Warehouse