Introduction

Our project is creating a hydroponic system for microgreens with a water parameter regulation system.

Microgreens

Microgreens are germinated seeds that have grown their primary or ‘true’ leaves. Many of them offer many times more nutrients per gram compared to their mature counterparts.

Germination of microgreens requires a weighing down and blackout state for consistent and healthy growth. Weighing down helps with fostering strong straight even stem growth so they are not limp or spindly. This prevents the seedlings from growing sideways under another and inhibiting it from photosynthesising later on hence dying and rotting. Blacking out is also for even germination so that the seedlings would grow evenly. This prevents disease and fungal growth should those seedlings that germinated first start growing towards the light and shadowing those under it. Weighing down and blacking out is especially important for microgreens due to the size of their primary leaves and the high seed sowing density.

Hydroponics

Regular hydroponics systems are for growing seedlings to maturity which reduces the complexity of having to germinate the seeds, blacking them out and weighing them down. They are germinated in rockwool or other substrates individually and transplanted into the hydroponic system as seedlings to grow. As the roots are grown into the substrate, it is not reusable and generates waste. Growing plants to maturity also takes, on average, months.

Our hydroponics system aims to remove the use of substrate by using reusable frames. Germination, blacking out and weighing down for healthy and full yield of microgreens are all to be done on the frames. The nutrient solution for the growth of the seedling is also used for the germination of the seeds. Germination and growth of a microgreen usually takes up to two weeks.

Goal

Our main focus for design and innovation comes from the growing frames and our biggest challenge is the automation of the dosing system.

Growing frames

We aim to be able to germinate and grow microgreens on the frames without needing to transplant the seedlings. This means that we need to accommodate the various seed sizes, blackout and weighing down periods on that frame. This proved to be quite a task as there needed to be a constant water level so as to not flood or dry out the microgreens.

Dosing system

We aim to automate the dosing pump to ensure the pH levels of the nutrient water is within specified constraints. We would also monitor and regulate the nutrient concentration of the water and automate the lights to ensure that the microgreens are able to grow in optimum conditions.