[clothahump]

I should imagine the blue filter media to be some type of foam which is a good home for bacteria.
Why bother with carbon? it is a functional media but tends to dump all the contaminants back into the water if left for two long.
I would add some gravel as the fish feel more at home, bare bottoms reflect the light back up unsettling the fish.
10 gallons for marine use will be very unstable, and you will have to constantly test the parameters,bigger is better in this case. 8)