Usually, hydroponics systems require a flow rate of 100 gph for a single grow bed loop of maximum 120 ft. Drain or flood beds require minimum 2 and maximum 4 cycles an hour. It would also be required to find the system lift. This is measured in terms of the vertical distance between the discharge point of the pump and the top level of water inside the pump tank.
There are many other considerations with regard to the choice of the submersible pump. The life of the pump increases significantly if you choose constant pump duty cycle rather than intermittent cycle. This would eliminate the need for a level or timer control. Keep in mind that a pump is going to last between 2 to 4 times the printed warranty period.
Usually, it is not required to have a foam filter for the submersible pump, as a screen cover is more than enough. Chances are that the foam filter is going to clog the pump fast. Micro-algae are also a concern, but are not a problem unless the water flow is affected. Keep these points in mind and make sure to get more information online before choosing the ideal pump.