Week 9 – Late Ripening, Root Zone Reset & Canopy Management
Entering Week 9 puts us squarely on the home stretch.
Transpiration has noticeably tapered off as the plants wrap up floral development, which made the stubborn 6.7–6.8 runoff pH even more critical to resolve before the final flush.
With nutrient demand declining and runoff volumes climbing, I made key structural adjustments to dial in the finish line:
Eliminating the Silicate Buffer:
The root cause behind the elevated runoff pH was Silic Rock (potassium silicate). At this late stage, its strong alkaline buffering was continuously fighting the acidification and blunting the action of Athena Cleanse. I dumped the remaining reservoir and mixed a fresh 35 L batch (EC 1.0 mS/cm, initial pH adjusted to 5.4)—**completely cutting out Silic Rock** while maintaining a 0.2 ml/L dose of Cleanse for root and line hygiene. Dropping the silicate frees the root zone to sit naturally in the optimal coco absorption band.
Metabolic Shifts Under High DLI & CO₂:
The plants have been pushed hard under high light intensity and CO₂ supplementation throughout bulk bloom. Heavy phosphate uptake in prior weeks, coupled with an anion/cation exchange that pushes hydroxyl ions OH into the rhizosphere, left behind concentrated salt pockets in the coco core as transpiration outpaced nutrient consumption.
Canopy Thermal & Radiation Relief:
Looking closely at the main colas directly beneath the fixture's center, several top pistils showed early browning and heat stress. This was photo-oxidation from high PPFD rather than uniform trichome maturity. To relieve canopy stress and protect ripening calyxes, I raised the LED fixture by 10–15 cm, dropped ambient temperature by 2°C, and increased relative humidity by 2% to bring the VPD into a gentle, non-stressful range for the final fade.
Phenotypic Variances (Seed vs. Clone):
Operating four distinct seed-grown phenotypes under an automated dripper setup requires keen observation. Plant #3 developed a noticeably denser root block with slower drainage, requiring targeted manual top-offs to match the wash-through of the other three.
With the fresh, unbuffered reservoir locked in and light stress minimized, the canopy is cruising cleanly through Week 9 to finish cloudy and amber without salt buildup.
Day 58 / Week 9 – Official Start of Nitrogen Cut & Heavy FadeToday marks the official start of the Fade Out / N-Cut phase. This morning was the very last feeding containing any nitrogen; from here on out, it’s 100% zero-N all the way to harvest.These are the final snapshots of the green canopy before the full autumn fade sets in. The goal of this protocol is simple: force the plants to deplete their internal nutrient reserves and break down excess chlorophyll in both leaves and flower calyxes. Excess chlorophyll and lingering nitrates are the primary culprits behind harsh smoke and a grassy taste—cutting nitrogen now guarantees a silky-smooth smoke, clean white ash, and lets the authentic terpene profile shine without interference.Current Reservoir & Regime:Water: 100% pure RO (EC 0.0)Formula: Complete Nitrogen Cut (0 ml N-base). Running a specialized $text{CaCl}_2$ finish for calcium and cell wall rigidity without nitrogen, coupled with light PK and essential micros.Biostimulants: Chitosan oligosaccharide (systemic defense / SAR against botrytis) and Triacontanol + Kinetin for late-stage resin synthesis and terpene density.Parameters: Inflow EC 1.0 mS/cm, pH dialed in at 5.4–5.6 to clear the root zone buffering.Plant 1 is already wrapping up senescence with heavy calyx swelling and rich anthocyanin purples, while Plant 3 is finishing its final push of calyx stacking. The flush/fade clock is officially ticking!