Session 1 · DESIGN: Explore
Nitrogen cycle and system types
- 15 minThe invisible workers: act out the nitrogen cycle as fish, ammonia, bacteria, nitrite, nitrate and plants.
- 15 minCompare system types: media bed, floating raft, pipe (NFT) and wicking bed. What does each need?
- 15 minSite survey: measure the space, sunlight hours, distance to power and water, and who can check it daily.
- 5 minChoose your context: tank, wicking bed or both.
Session 2 · DESIGN: Sketch
System diagram and plan
- 20 minDraw a labelled system diagram: tank, pump, grow bed, flow direction, drain, and what each subsystem does.
- 15 minWrite the brief and three specs, e.g. 'must run a week without adding water', 'must fit on one bench', 'must use at least half recycled materials'.
- 10 minMaterials list with a reason for each and where it will come from.
- 5 minTeacher safety check of the design: electricity, water, weight.
Getting started
Use the diagram template with boxes for each subsystem.
Stretch
Draw the same system as a black box: only inputs and outputs. What do you lose by not seeing inside?
Checkpoint
A labelled system diagram and brief the teacher has safety-checked.
Activities for this week
- Nitrogen cycle role-play: How does fish waste become plant food?
Useful this week
- The nitrogen cycle ↗ How nitrogen moves between living things, soil, water and air.
- Water quality monitoring ↗ What scientists measure to judge water health, and why.
- How to make wicking garden beds ↗ Step-by-step build ideas for a self-watering bed.