The Problem

Yesterday morning, I had discovered that my automatic feeder on my aquarium had dumped its entire hopper in the aquarium (not a big deal, it was almost empty), and was unable to retract the hopper to the original position. I initiated a manual feed via a button on the back, and the hopper would just spin and never return to initial start position.

I initially thought that the gear mechanism had just gotten misaligned or stuck, I disassembled the feeder and reset the gears so that everything was in the correct initial state. Upon testing I ended up with the same result. This now meant that I had to figure out how the feeder knows when to retract the hopper back to the initial state at the end of the feed cycle.

Background

I have a 135gal saltwater aquarium in my office full of coral and several fish. The system is fairly automated, it is controlled by a commercially available aquarium controller running custom rules that I have programmed into it to control heaters, supplement dosing, pumps, UV sterilizer, Ozone reactor, etc. I’ll probably make a post at some point in the future explaining the setup.

The supplement dosing is the trickiest part of the whole system, it requires constant water parameter testing to ensure that the correct amount of supplements are being dosed, and I also have to ensure that I don’t run out of the supplements. As I get busy with life, kids, work, etc, inevitably I forget to check the containers of supplements and the system doses nothing to the tank for days or weeks until I remember to check them.