Setup​

• Medium: Rockwool (6” cubes)
• Irrigation: Microdrippers (drain-to-waste)
• Water EC: ~0.5–0.6 (tap water)
• No full climate control (temperatures can reach ~30°C+)
• Nutrient formulation designed with HydroBuddy
• Goal: simple, repeatable, salt-based feeding

Vegetative Phase (Day 0–14)​

Per 10L:

• Peters 6-18-36 → 6.5 g
• Calcinit → 5 g
• MgSO4 → 3.5 g

Targets:

• EC: 1.2 → 1.6
• pH: 5.5 → 5.7

HydroBuddy screenshot:

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Stretch Phase (Flower Day 1–21)​

Per 10L:

• Peters → 7.5 g
• Calcinit → 6 g
• MgSO4 → 3.5 g
• MKP → 0.5 g

Targets:

• EC: 1.5 → 1.7–1.8
• pH: 5.6 → 5.8

Objective: controlled stretch without excessive generative push.


HydroBuddy screenshot:

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Bulk Phase (Flower Day 22–48)​

Per 10L:

• Peters → 8.25 g
• Calcinit → 3.5 g
• MgSO4 → 3 g
• K2SO4 → 0.9 g
• MKP → 0 g

Targets:

• EC: 1.9 → 2.3–2.4 → 2.0
• pH: 5.7 → 5.9

Strategy: higher potassium, reduced nitrogen for density and yield.


HydroBuddy screenshot:

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Finish (Flower Day 49–59)​

Per 10L:

• Peters → 4 g
• MgSO4 → 2.5 g
• K2SO4 → 1.25 g
• MKP → 0.5 g
• No Calcinit

Targets:

• EC: 1.5 → 1.1
• pH: 5.8 → 6.0

Low-nitrogen finish


HydroBuddy screenshot:

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Environmental Adjustments​

• High temperature (>30°C): reduce EC by ~0.2
• Normal: no adjustment
• Low temperature (<22°C): increase EC by ~0.1

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Irrigation Notes​

• Drain-to-waste with 10–20% runoff
• Using Growlink with substrate sensors to run a VWC-driven irrigation strategy, instead of fixed timer schedules.
• Monitoring drain EC and pH
• Monitoring substrate EC
• Avoiding salt accumulation
• Frequent, smaller irrigation events preferred over large infrequent ones

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Design Approach​

• Keep inputs simple (no unnecessary additives)
• Use EC as the main control variable
• Allow pH drift within range rather than fixing a single value
• Maintain a clean system using HOCl

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Questions​

I would appreciate feedback on the following points:

1. Phosphorus levels during bulk
   Currently around ~60–65 ppm from base nutrients only (no MKP). Is this still slightly high or acceptable?
2. Potassium level in finish (~200–220 ppm)
   Is this optimal for ripening, or would you adjust it?
3. Sterile system (HOCl)
   Any drawbacks in long-term rockwool drip systems?
4. Calcium removal in finish
   I rely on ~60 ppm from tap water. Would you still add a minimal amount of calcium, or leave it as is?

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Objective​

To build a system that is:

• stable
• reproducible
• low maintenance
• resistant to clogging
• high yielding