you can build a simple overshot wheel with more than 70% efficiency.
http://www.hp-gramatke.net/pmm_physi...h/page0450.htm
like i said in my first post, we would not want a tight fitting turbine. they require a higher head of water and flow which means back pressure and would overflow the tank. and could sieze up.
generator and inverter also mentioned in my first post. its all there. build one if you can. a simple engineering lab experiment to account for bucket volume to handle the flow, lever arm length, and shaft power and speed and pulley ratios.