Instruments
Tools
Mixer, DLI, system picker, and a leaf diagnostic from the advanced bench. They estimate. Your meter decides.
Nutrient mixer
Two-part tank mix
A starting estimate for a generic equal A+B concentrate. Confirm with a calibrated EC meter. Always A into water, then B.
- Part A
- 50 ml
- Part B
- 50 ml
- 500-scale
- 600 ppm
- 700-scale
- 840 ppm
Feed EC to add: 1.00 mS. Mix until clear, then pH last. This is not a brand feed chart.
Light
DLI calculator
Daily light integral from canopy PPFD and photoperiod. DLI = PPFD × hours × 0.0036.
DLI
14.4mol/m²/day
In range for lettuce and most leafy herbs.
Architecture
System picker
Four questions. One recommended architecture. Then go and learn that system properly.
Run this
Deep water culture
Fast vegetative growth with an air pump. Watch reservoir temperature like a hawk.
Open the systems mapField diagnosis
Reading a leaf
Mobile elements leave old leaves first. Immobile ones show on new growth. Pick what you see; the first move is a meter, not a bottle.
Where
Pattern
Iron — usually pH, not an empty bottle
Interveinal chlorosis on new leaves is Fe. EDTA drops out above ~6.3. Measure pH, then EC. If pH is high, correct it and wait 24 hours before adding more iron. Use DTPA or EDDHA if your source water is alkaline.