Automatic Feeder for aqua-cultures

I have been working on trying to come up with a design that would allow me to dose rotifers/algae or brine into a fish rearing tank or even a main tank.  The thought is to have a tank that has three separate compartments that could hold the aqua-culture and a bulk head attached to each compartment that has a sprinkler valve that is connected to a sprinkler timer.  This would allow the valve to open when it should feed the tank.  Any thoughts or has anyone seen something that would acheive the same thing?

Actually I was mainly looking at an automatic feeder of sorts that would dispense the aqua-culture into the system.  I actually have another idea on this since my idea on the sprinkler valves probably won't work.  The over all problem is that during the day I would want to dose the tank about 3-4 times, and it is nearly impossible for me to accomplish this as I work.  so my thought was to have a holding chamber that would have a valve that would 'dump' the food into the tank.  So the other idea is to use 2liter bottles and have a seal on it, a line that runs into the bottle above the fill line, and a second one below the water near the bottom.  The line above the fill line would then be attached to an air-pump to provide pressure in the bottle, thus forcing the aqua-culture through the other line.  The problem with that is I would need to have a timer and pump for each bottle.  This would only allow me to put in fresh aqua-cultures each day, so I would need a separate setup for the culturing.