Formally speaking, from a textbook I was an editor on:
Aero-Cloning Protocol
The procedure is organised in five modules:
I. Equipment sanitisation & reservoir recipe
II. Mother-plant preparation (pre-cut)
III. Excision technique-exact cut geometry & handling
IV. Aerocloner loading & early-rooting care
V. Hardening-off & transplant
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I. EQUIPMENT SANITISATION & RESERVOIR SET-UP
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Disassemble the aerocloner: lid, neoprene collars, pump, sprayers.
Wash every part in hot tap water + non-detergent lab soap; rinse.
Soak 20 min in 2 % v/v sodium hypochlorite (≈ 1:25 household bleach).
Rinse twice with RO water, then final rinse with 70 % iso-propyl alcohol; air-dry.
Re-assemble; fill reservoir with the following rooting solution:
• RO or de-ionised water ………………… 100 %
• pH ……………………………………… 5.8 ± 0.1 (use 70 % phosphoric acid)
• EC ……………………………………… 0.3 mS cm⁻¹ (≈ 150 ppm)
• Dissolved O₂ ………………………… ≥ 8 mg L⁻¹ (achieved by ½-inch air-stone or venturi pump)
• Additives (per litre):
– Kelp extract (0-0-1) ……… 0.5 mL
– B-vitamin complex ………… 0.25 mL
– 0.02 % H₂O₂ (food-grade) … 0.2 mL (keeps bioburden low)
NOTE: No base nutrients yet; nitrate suppresses early root initiation.
Turn pump on, verify 360° spray pattern; water temp should stabilise at 20–22 °C.
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II. MOTHER-PLANT PREPARATION (48 h BEFORE CUTTING)
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Select branches with internode diameter 3–5 mm, fully turgid, free of pests.
Irrigate mothers with plain pH-adjusted water 24 h pre-cut to flush excess nitrogen (reduces leaching & stem rot).
Dim overhead light to 400 µmol m⁻² s⁻¹ PAR for last night to maximise carbohydrate reserves.
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III. EXACT CUTTING TECHNIQUE
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A. Tools (sterile)
• Surgical scalpels #11 or fresh single-edge razor blades
• Fine scissors for leaf trimming
• 70 % IPA spray & flame source (pass blade through flame after IPA)
• Hormone: 0.3 % IBA gel (e.g.,
Clonex) or 2 g L⁻¹ IBA quick-dip
B. Excision sequence (one cutting at a time; total dwell time in air 45 s)
Step 1 – Primary severance
• Identify a branch tip with 2–3 fully expanded leaves and one developing node.
• Make a FIRST CUT 15 cm below the apex using scissors-this is a rough cut to detach the shoot, minimising mother stress.
Step 2 – Immediate hydration
• Place the excised shoot into a beaker of chilled, aerated RO water (pH 6).
Step 3 – Final basal cut (critical geometry)
• On a sterile glass plate, retrieve the shoot and, under water (submerged method: prevents xylem cavitation), make the FINAL CUT:
– Angle … 45 °
– Position … 3–4 mm below a node (node tissue contains more meristem).
– Length left under node … 8–10 mm.
• Optionally shave a 3 mm strip of outer cortex on one side (exposes cambium-boosts root initials).
Step 4 – Leaf trim
• Retain two full leaves; clip their blades to 35–40 % of original area (lowers transpiration; preserves photosynthate).
Step 5 – Hormone application
• Blot stem gently on sterile gauze.
• Dip 15 mm of the base into IBA gel for 5 s OR 2 s in liquid IBA, then tap off excess.
Total time from water to collar ≤ 30 s.
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IV. AEROCLONER LOADING & EARLY CARE
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Insert stem through a labelled neoprene collar; ensure ≥ 40 mm of stem hangs below lid.
Maintain spacing ≥ 5 cm between collars for uniform spray.
Photoperiod: 18 h light / 6 h dark; PPFD 100–120 µmol m⁻² s⁻¹ (T5 or LED).
Air-temp 24 °C day / 22 °C night; reservoir 20–22 °C; RH 80–90 %.
Pump cycle: continuous or 1 min ON / 1 min OFF (avoid stagnant droplets).
Daily checks:
• Top up RO water to original level; re-balance pH 5.7–5.9.
• Replace 20 % of solution every 48 h; full change Day 6.
• Inspect collars for slime; wipe lid underside with 50 ppm hypochlorite cloth.
• Remove any yellowing leaves (ethylene source).
Expected timeline (Cannabis):
• Day 3–4 …… callus ring visible
• Day 5–7 …… root initials (1–2 mm)
• Day 8–10 … 3–5 adventitious roots, 1 cm long
• Day 11–14 … ready to transplant (roots ≥ 4 cm, lateral branching)
If roots are 8 cm and entangling, transplant immediately; prolonged aero-culture causes brittle roots.
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V. HARDEN-OFF & TRANSPLANT
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Prepare substrate (rock-wool cube, peat plug or coco mix) pre-soaked with 0.5 mS cm⁻¹ starter nutrient, pH 5.8.
Transfer cutting; gently guide roots downward-do not bend.
Dome RH 95 % for 24 h, then crack vents gradually to 60 % over 4 days.
First feed at 0.8 mS cm⁻¹, 24 h post-transplant; increase to production EC by Day 7.
Light: raise to 250 µmol m⁻² s⁻¹ by Day 5 to trigger vegetative surge.
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CRITICAL CONTROL POINTS & TROUBLESHOOTING
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• Stem rot / grey slime → verify water temp 23 °C, H₂O₂ 0.02 %, spray nozzles free.
• No roots by Day 10 → pH drifted high? IBA expired? Replace solution, check TDS.
• Leaf wilt in first 48 h → RH too low; mist underside, lower PPFD temporarily.
• Browning root tips → salts accumulating; full reservoir change, confirm EC ≤ 0.4 mS cm⁻¹ until roots 2 cm.
