I need a new air pump for my fish room. Currently running a 50l/min Yamitsu LP50. I have 26 air filters running and it just doesnt have enough 'umph'! The filters in my deeper tanks (just 18 inches deep) are not running, so i need to put bog wood under them so the water pressure is less. Then they work ok. But air stones dont work as they have too much resistance. Anybody in the know....do i need more pressure? higher flow rate? Both? Suggestions as to a pump? I dont care about the noise as its in the fish room in the garage. But low wattage is good....more importantly low in price!!