yes it is but only because I lost a few due to ick. Ok 15 - 20 cory's sounds great.
What else? How about Dwarf Gauramis? More Tetras? Barbs?

I currently have 5 black skirt tetras, 3 rainbows, 1 panda cory, 2julli cory's.
What else can i put in this tank and how many of each? I love the cory's! I really like shoaling fish!