There are plenty of dosing pumps on the market that I could purchase to automate this dosing process, but that's no fun so I'm going to build my own. Even though I'm building this dosing pump ...

The DC water pumps are attached to the nutrient solution ... The below video shows a brief working of this project: (💡 PS - Due to financial constraints, we have not used the EC sensor & pH up / down ...

[Gonzho] has been busy the last few years working on his own Arduino Powered Open Source heat pump controller, and the project logs show some nice details of what it takes to start experimenting ...