First of all I don't have an aquarium or bird to feed :).
I designed this model for experimental purposes and entertainment. Nevertheless it works great and seems accurate.

I have used the equipment on hand:

• 20rpm 50KTYZ Motor (110/220V)
• Standard WIFI Switch (ie SONOFF basic).

I would advise you to use a low voltage stepper motor and aurdino for programming instead of the above equipment (which will of course require some modificaitons on the model by using ie Tinkercad or similiar 3d design software).

WARNING: Safety First! Dealing with high voltage (ie 110/220V) especially where there is water, is dangerous and may harm you or worse. Please disconnect all electricity plugs before you do any work on the power outlets/plugs and cables. Take care of short-cuts, weak cables, connections and switches which may also casue electric shock, burns and other fire risks. Do not insert the model or put the model somewhere falling hazard to water.

WARNING & DISCLAIMER: This DIY project is not a proffessional study. Failure of proper working of the parts or devices may cause harm to you and to your animals. Accordingly, install and use the model at your own risk. I assume no resposibility in this respect.

The model is composed of 5 printable parts:
1) Base
2) Piston
3) Arm
4) Wheel
5) Lid for storage cover (optional).

Your wifi switch's mobile app should be capable of "inching". Inching means that the switch will be on for a determined time period (ie 3 seconds) and then goes off until next triggering.
You program triggering the switch by your mobile app to perform the feeding on a routin (ie everyday at 10am) based on your needs (or your animals')
So, the program will turn on your switch at the specified time for 3 seconds and then goes off until the next specified triggering time, as desired. 3 seconds is accurate time for a 20rpm motor to make one cycle (60/20=3) where the piston will push out of the tube enough feeding stuff collected inside the tube (ie 5gr) and the piston will be back to its original position and stop. The piston's position is not so much important, becasue it will complete 1 cycle each time when triggered and gravity will feed the tube everytime.

Happy feed..sorry printing:)

3D PRINTING SETTINGS
Infill:
Base & Lid >=10%
Other parts >=20%
No supports or Build Plate Adhesions needed.