I am starting a riparium, and I am wondering where I should place my Tetra internal 30i filter (stupid question I know). My tank is a 20g high, with no hood. The filter is about 10in tall, and the water level is about 7in+. Would it be fine if I put part of the intake in my subtrate (which is normal aquarium gravel)? Should I place it in the middle of my tank or?