⚠️ DEV BUILD — All calculators enabled for testing. Not for production use.
Athena
Toolbox

Athena Toolbox

Precision tools for cultivation professionals

📊
Dry Back Calculator
Calculate target VWC% for generative or vegetative steering
AVAILABLE
🌊
RDWC Nutrient Calculator
Addback calculations for recirculating deep water culture systems
IN TESTING
💉
Netaflex Injection System
Configure injector settings for Netaflex Pro Line nutrients
IN TESTING
🧪
EC Blending Calculator
Blend nutrient solutions to hit your target EC
COMING SOON
🌡️
VPD Calculator
Vapor pressure deficit for optimal climate control
COMING SOON
💧
Water Volume Calculator
System volume calculations for RDWC setups
COMING SOON
Inputs
%
%
Dry Back VWC% Goal
60% × (1 − 0.40) = 60% × 0.60
36%
Dry Back Range Context
Your dry back: 40% — Moderate
Wetter (veg) Drier (gen)
🔥 Generative
40–50%
Dry back
🌿 Vegetative
20–40%
Dry back
At 40% dry back, you're in generative territory — steering the plant toward fruiting and reproductive growth.
Dry Back Curve Visualization
📖 What is Dry Back?

Dry back is the intentional reduction of substrate VWC% (volumetric water content) between irrigation events. After reaching peak VWC at field capacity, the crop is allowed to transpire and deplete moisture to a target level before the next irrigation cycle.

Managing dry back gives you direct control over plant stress response, root development, and generative vs vegetative growth balance.

⚖️ Generative vs Vegetative
  • Generative Higher dry back (40–50%+) — triggers stress response, promotes flowering, fruiting, and root zone development. Less water = reproductive signal.
  • Vegetative Lower dry back (20–40%) — keeps substrate wetter, promotes shoot growth, canopy expansion, and vigorous vegetative development.
  • Transition timing and magnitude determine how aggressively you steer the crop.
📐 How to Use This Calculator
  • Set Target Peak VWC% to the water content at the top of your irrigation cycle (field capacity for your substrate).
  • Set Dry Back % to how much you want to reduce from peak.
  • The Dry Back VWC% Goal is the substrate reading where you trigger the next irrigation.
  • Monitor your substrate sensors and irrigate when VWC hits the goal.
🔗 Resources
  • Athena crop steering protocols vary by cultivar, growth stage, and environment. Calibrate with your local data.
  • Dry back targets interact with EC strategy — a heavier dry back often pairs with lower frequency, higher EC shots.
  • Sensor placement matters: measure at mid-slab, not edges.
📄 Plant Irrigation Strategy (PIS) — link coming soon
System Configuration
EC Readings
defaults to Feed Schedule EC — adjust if targeting partial addback
Current EC
0.20
mS/cm
Target EC
0.33
mS/cm
Addback EC Needed
0.13
mS/cm
✅ No addback needed — tank EC meets or exceeds target.
Addback Volumes Veg Week 0
Nutrient mL / Gallon Total mL (system)
💡 How to use: Add total mL of each nutrient to your tank. Re-check EC after mixing and allow 5–10 min to stabilize before adjusting further.
Inputs
gal
Calculated Outputs
Grams per Gallon
- g/gal
From EC lookup table
Stock Tank mL/Gallon
- mL/gal
Concentrate volume per gallon of irrigation water
NMC Setting (mL/gal)
- mL/gal
Program this into your NMC controller
NMC Setting (Injector %)
- %
Alternate NMC input as injection percentage
Injector Pump Flow Rate
- mL/min
Set your rotometer to this value
Total Injection Volume
- mL/hr
Concentrate used per hour of irrigation
🌿 Product Difference
  • Pro Bloom & Pro Grow use the same dosing column — both are 2-part base nutrients for their respective stages.
  • Pro Core uses a separate, lower dosing rate — it's a concentrated micronutrient blend used alongside Bloom or Grow.
  • When running a full program, calculate each product separately and set individual injector channels.
🏗️ Stock Tank Concentration

The amount of dry fertilizer dissolved per gallon of water in your stock (concentrate) tank. Higher concentration = less volume needed per gallon of fertigation water.

  • 1 lb/gal — light mix, easy to dissolve, larger tank required
  • 2.5 lb/gal — concentrated, smaller tank, more dissolve time
  • Liquid — Athena Liquid Pro Line, pre-dissolved
⚙️ NMC Setting Explained

The NMC (Nutrient Management Controller) takes either a mL/gal or an injector % as its input. Both values represent the same thing — how much concentrate to inject per unit of water.

  • mL/gal — direct volume ratio for volume-based NMC inputs
  • Injector % — percentage of system flow injected (e.g. 0.85% means 0.85 mL per 100 mL water)
📐 Injector Pump Flow Rate
  • Calculated from your system flow rate and g/gal dose. Set your rotometer or pump dial to this mL/min value.
  • System Flow Rate: Total irrigation water flow in gal/min at the injector point.
  • Use Total Injection Volume (mL/hr) to estimate stock tank usage per irrigation cycle.
Tank Inputs
Tank A
Tank B
Target
Blend Results
Volume from Tank A
gal
EC: — mS/cm
Volume from Tank B
gal
EC: — mS/cm
Total Blend Volume
gal
Combined total of A + B
Resulting EC (validation)
mS/cm
Should match your target EC
Blend Ratio A : B
Parts Tank A to parts Tank B
Tank A Tank B
—% —%
📐 How the Math Works

Uses the standard mixing formula: blendEC = (volA × ecA + volB × ecB) / totalVol. Solve for volA: volA = (targetEC − ecB) × totalVol / (ecA − ecB). Tank B volume = total − volA.

💧 Tank B as RO Water

Set Tank B EC to 0.0 to use pure RO water as your dilutant. This is the most common use case — diluting a concentrated nutrient solution to a target feed EC.

⚠️ Volume Constraints

The calculator checks that required volumes don't exceed what's available in each tank. If Tank A or B doesn't have enough volume to hit the target EC, an error will show with the maximum achievable EC given your constraints.

🎯 Best Practice
  • Always verify with a calibrated EC meter after blending.
  • Allow 5–10 min for full mixing before final EC check.
  • Temperature affects EC — measure at consistent temps.
🌡️
VPD Calculator
🔧 COMING SOON — DEV BUILD

Tab accessible in dev mode for navigation testing.
Logic not yet implemented.

🪣
Water Volume Calculator
🔧 COMING SOON — DEV BUILD

Tab accessible in dev mode for navigation testing.
Logic not yet implemented.