I am wanting to increase the water flow in my 14g Biocube but not wanting to give any precious real estate over to an unsightly powerhead. So I thought that I could perhaps upgrade the circulation pump in the back chamber giving more flow to the tank. I believe the stock pump delivers 135gph so I would want to increase that by at least double. Does anyone know what pumps would fit in the back chamber? Anyone modified a 14g in this way that can share some knowledge?