Proto 3: The Agrosphere—Bringing It Full Circle
It all started because I wanted to get the carbon out of my salad.
Now, after Proto 0 (proof of concept), Proto 1 (Saunosphere), and Proto 2 (Immosphere), we're finally ready to build the thing that inspired everything: the Agrosphere.
A mobile, modular greenhouse that fits in half a parking spot.
Why We Waited
The Agrosphere is the most complex configuration:
Saunosphere needs: Heat, ventilation, seating
Immosphere needs: Power, climate control, technology
Agrosphere needs: All of the above, plus water management, plant support, environmental monitoring, and automation
We needed to learn how to:
- Manage thermal performance (Saunosphere)
- Integrate electrical systems (Immosphere)
- Control climate precisely (Immosphere)
- Document complex builds (both)
Now we're ready.
The Design Requirements
Environmental Control
Plants are demanding. They need:
Light:
- Full spectrum LED grow lights
- 12-16 hours per day for most crops
- Adjustable intensity and spectrum
- Supplemental natural light when possible
Temperature:
- 65-75°F for most crops
- Consistent day/night temperatures
- No sudden fluctuations
- Protection from extreme heat/cold
Humidity:
- 50-70% relative humidity
- Varies by crop and growth stage
- Too low = stressed plants
- Too high = disease and mold
Air circulation:
- Gentle airflow (simulates outdoor breeze)
- Prevents mold and disease
- Strengthens plant stems
- Distributes CO2 evenly
Water Management
This is the big one. Water is life, but it's also the hardest system to manage.
Irrigation:
- Automated drip system (most efficient)
- Timer-based or sensor-triggered
- Adjustable for different crops
- Easy to maintain and clean
Drainage:
- Catch excess water
- Prevent standing water (root rot)
- Recirculate when possible (water conservation)
- Easy to empty and clean
Humidity control:
- Dehumidifier for excess moisture
- Humidifier for dry climates
- Integrated with climate control
Plant Support
Shelving:
- Modular, adjustable height
- Strong enough for soil containers
- Allows airflow between levels
- Easy to reconfigure
Growing systems:
- Soil containers (traditional, forgiving)
- Hydroponic (efficient, faster growth)
- Aeroponic (advanced, maximum efficiency)
- Aquaponic (integrated fish/plant system)
We're starting with soil containers (simplest) but designing for future hydroponic upgrades.
Monitoring and Automation
Sensors:
- Temperature (multiple zones)
- Humidity (ambient and soil)
- Light levels (ensure adequate coverage)
- Soil moisture (prevent over/under watering)
- pH (for hydroponic systems)
Controls:
- Automated lighting (on/off, dimming)
- Automated irrigation (scheduled or sensor-triggered)
- Climate control (heating, cooling, ventilation)
- Remote monitoring (smartphone app)
Data logging:
- Track environmental conditions
- Identify patterns and problems
- Optimize growing conditions
- Share data with community
The Build Plan
Phase 1: Structure (Week 1-2)
Same as previous prototypes:
- Elevated base platform
- Geodesic frame
- Exterior panels (mix of transparent and opaque)
- Weatherproofing
Agrosphere-specific:
- More transparent panels (maximize natural light)
- Reinforced floor (water weight)
- Drainage ports in base
Phase 2: Systems (Week 3-5)
- Electrical installation (lights, pumps, controls)
- Plumbing (water supply, drainage)
- HVAC (heat pump, ventilation)
- Network (WiFi for sensors and controls)
Complexity: This is where the Agrosphere gets challenging. Water + electricity = careful planning.
Phase 3: Interior (Week 6-7)
- Insulation (thermal performance)
- Interior panels (waterproof materials)
- Shelving installation (modular system)
- Lighting mounting (LED grow lights)
Phase 4: Water Systems (Week 8-9)
- Irrigation system (drip lines, emitters)
- Drainage system (catch basins, pumps)
- Water storage (reservoir for recirculation)
- Testing (leak check, flow rates)
Phase 5: Automation (Week 10-11)
- Sensor installation (temp, humidity, moisture)
- Control system setup (timers, triggers)
- Software configuration (automation rules)
- Testing and calibration
Phase 6: Growing (Week 12+)
- Soil and containers
- First crops (leafy greens, herbs)
- Monitoring and adjustment
- Harvest and evaluation
Timeline: 12+ weeks (ongoing growing experiments)
Cost: $10,000-$15,000 (structure, systems, automation)
The Crops
What can you grow in 64 square feet?
High-Value, Fast-Growing Crops
Microgreens (1-2 week cycle):
- Sunflower, pea shoots, radish
- $20-30/lb retail
- 10 lbs per harvest
- 26-52 harvests per year
- Annual potential: $5,200-$15,600
Leafy Greens (4-6 week cycle):
- Lettuce, arugula, spinach, kale
- $4-10/lb depending on market
- 40 lbs per harvest
- 8-13 harvests per year
- Annual potential: $1,280-$5,200
Herbs (ongoing harvest):
- Basil, cilantro, parsley, mint
- $12-20/lb retail
- 20 lbs per month
- Year-round production
- Annual potential: $2,880-$4,800
Specialty Crops
Mushrooms (controlled environment ideal):
- Oyster, shiitake, lion's mane
- $12-20/lb
- Can grow in lower light areas
- Complements greens production
Strawberries (vertical growing):
- $5-8/lb
- Year-round production possible
- High demand, premium pricing
Tomatoes/Peppers (longer cycle):
- 8-12 week cycle
- $3-6/lb
- Lower volume but popular
The Strategy
Start simple:
- Microgreens (fast, forgiving, profitable)
- Leafy greens (steady production, reliable market)
- Herbs (high value, continuous harvest)
Then expand: 4. Specialty crops (mushrooms, strawberries) 5. Experimental crops (community requests, local demand)
The Economics (Revisited)
Now that we're actually building it, let's update the numbers:
Investment:
- Structure and systems: $12,000
- First year supplies (seeds, soil, nutrients): $500
- Total: $12,500
Operating Costs (monthly):
- Electricity (lights, climate, pumps): $75
- Water: $15
- Seeds and supplies: $50
- Total: $140/month = $1,680/year
Revenue (conservative - wholesale leafy greens):
- 40 lbs per harvest
- 10 harvests per year (learning curve)
- $4/lb wholesale
- Total: $1,600/year
First year: Slight loss (learning, establishing systems)
Revenue (optimistic - mixed production):
- Microgreens: $8,000
- Leafy greens: $2,000
- Herbs: $3,000
- Total: $13,000/year
Profit: $11,320/year after operating costs
Payback: ~13 months
Year 2+: Pure profit (structure is paid off)
The Real Value
But the Agrosphere isn't just about profit. It's about:
Food security: Fresh produce year-round, regardless of season or supply chain.
Nutrition: Harvest-to-plate in hours, maximum nutrient retention.
Education: Learning where food comes from, how to grow it.
Community: Sharing harvests, knowledge, and resources.
Resilience: Distributed food production, less vulnerable to disruption.
Empowerment: Taking control of your food supply.
You can't put a price on that.
The Challenges
We know this will be hard:
Water management: Leaks, drainage, humidity—water is tricky.
Plant health: Pests, diseases, nutrient deficiencies—plants are complex.
Automation reliability: Sensors fail, timers malfunction, software bugs.
Learning curve: We're not professional farmers (yet).
Documentation: How do we teach people to grow, not just build?
But that's exactly why we're doing this. We need to:
- Make mistakes so others don't have to
- Develop robust systems that work reliably
- Create guides that teach growing, not just construction
- Build a community of growers who help each other
The Community Aspect
The Agrosphere is where the community becomes critical.
We can design the structure. We can engineer the systems. But we can't know:
- What grows best in every climate
- What local markets want
- What pests are common in each region
- What techniques work in different conditions
The community will figure this out. Growers in Texas will learn different things than growers in Maine. Someone will discover a better shelving layout. Someone will optimize the lighting schedule.
And because it's open source, everyone benefits.
The Documentation Plan
For the Agrosphere, we're creating:
Build Guide:
- Complete assembly instructions
- Electrical and plumbing diagrams
- Parts list and sourcing guide
- Video tutorials
Growing Guide:
- Crop selection for beginners
- Planting schedules
- Pest and disease management
- Harvesting and post-harvest handling
Automation Guide:
- Sensor installation and calibration
- Control system setup
- Automation rules and logic
- Troubleshooting
Business Guide:
- Market research and pricing
- Sales channels (farmers markets, restaurants, CSA)
- Licensing and regulations
- Scaling strategies
The Vision Realized
When we complete Proto 3, we'll have proven the full vision:
A modular, open-source platform that can be:
- A sauna (wellness)
- An immersive media space (entertainment)
- A greenhouse (food production)
- And dozens of other configurations
All built on the same basic framework. All documented and open source. All accessible to anyone with basic tools and skills.
This is what we set out to create.
The Timeline
We're planning to start Proto 3 in summer 2025, after Proto 2 is complete and documented.
This gives us:
- Time to incorporate lessons from Proto 2
- Time to source specialized components (grow lights, sensors, pumps)
- Time to connect with experienced growers for advice
- Time to build excitement in the community
Full Circle
From a sketch on a receipt to a working greenhouse.
From "I want to get the carbon out of my salad" to "here's how anyone can grow their own food in half a parking spot."
From an idea to a movement.
Proto 3 is where it all comes together.
And then? Then we share it with the world.
Next Post: Whole Earth: Standing on the Shoulders of Giants
Previous Post: Proto 2: The Immosphere Challenge
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