Free Hydroponic & Soil Growing Guides

Exact pH, EC, temperature, humidity, VPD and DLI targets for cannabis, vegetables, herbs, and fruits — in hydroponics and soil. Every guide is written to help you grow more with less guesswork.

Cannabis Grow Guides

Cannabis

Cannabis VPD Chart — Stage-by-Stage Targets

Seedling through flush VPD targets. Calculate VPD, fix high/low readings, and maximise transpiration.

VPD · kPa · Temperature · Humidity
Cannabis

Cannabis pH Guide — Hydroponic & Soil Targets

Ideal pH for every growth stage. Fix pH drift, diagnose lockout, and choose the right pH meter.

pH · Nutrient Lockout · DWC · Coco · Soil
Cannabis

Cannabis Temperature Guide — Day & Night Targets

Optimal day/night temps for veg and flower. Fix heat stress, cold stress, and DIF management.

°F · °C · Day/Night DIF · Heat Stress
Cannabis

Cannabis Humidity Guide — RH by Stage

Relative humidity targets from seedling to harvest. Prevent bud rot, mold, and powdery mildew.

RH% · Bud Rot · Mold · Dehumidifier
Cannabis

Cannabis EC & Nutrient Guide — mS/cm Targets

EC and PPM targets for every growth stage. NPK ratios, Cal-Mag, flushing, and deficiency diagnosis.

EC · PPM · mS/cm · NPK · Cal-Mag
Cannabis

Cannabis CO₂ Guide — PPM & Enrichment

How to use CO₂ enrichment to boost yields up to 40%. Methods, safety, and when it's worth it.

CO₂ · PPM · Enrichment · PPFD

Monitor every parameter automatically

GrowAI tracks pH, EC, VPD, CO₂, temperature and humidity — and alerts you before problems hurt your yield.

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Vegetable Grow Guides

Vegetables

How to Grow Tomatoes Hydroponically

pH 5.8–6.3, EC by stage, Dutch Bucket systems, blossom drop prevention, and harvest timing.

pH 5.8–6.3 · EC 1.0–4.5 · DLI 20–30
Vegetables

How to Grow Lettuce Hydroponically

NFT, raft, and Kratky targets. Prevent tip burn and bolting. Harvest in 28–60 days.

pH 5.5–6.5 · EC 0.8–2.0 · DLI 12–17
Vegetables

How to Grow Spinach Hydroponically

Cool-season targets, bolting prevention, and cut-and-come-again harvesting technique.

pH 6.0–7.0 · EC 1.2–2.2 · Temp 50–70°F
Vegetables

How to Grow Peppers Hydroponically

Bell pepper and hot pepper pH, EC, fruiting temperature, pollination, and yield targets.

pH 5.5–6.5 · EC 2.0–3.5 · DLI 20–30
Vegetables

How to Grow Cucumbers Hydroponically

English vs pickling varieties, Dutch Bucket systems, parthenocarpic pollination, bitter fruit causes.

pH 5.5–6.0 · EC 1.7–3.5 · DLI 20–30
Vegetables

How to Grow Kale Hydroponically

NFT and DWC targets, cold sweetening technique, and variety comparison for indoor growing.

pH 5.5–6.5 · EC 1.5–2.5 · DLI 12–20
Vegetables

How to Grow Swiss Chard Hydroponically

pH, EC, temperature targets, rainbow chard varieties, and multi-cut harvest method.

pH 6.0–7.0 · EC 1.5–2.5 · DLI 12–18
Vegetables

How to Grow Arugula Hydroponically

Fastest hydroponic crop at 21 days. Flavor chemistry, bolting prevention, succession planting.

pH 6.0–7.0 · EC 1.2–1.8 · Harvest 21–35 days
Vegetables

How to Grow Green Beans Hydroponically

Pole vs bush beans, DWC and Dutch Bucket setup, nitrogen fixation in hydro, harvest timing.

pH 6.0–6.5 · EC 1.5–2.5 · DLI 18–25
Vegetables

How to Grow Radishes Hydroponically

Root development in hydro systems, photoperiod impact, variety comparison, harvest at 22–35 days.

pH 6.0–7.0 · EC 1.2–2.0 · Harvest 22–35 days
Vegetables

How to Grow Beets Hydroponically

Grow both roots and greens, boron requirements, blackheart prevention, variety guide.

pH 6.0–7.0 · EC 1.6–2.5 · DLI 15–20
Vegetables

How to Grow Snap Peas Hydroponically

Cool-season targets, trellis requirements, powdery mildew prevention, harvest at 60–70 days.

pH 6.0–7.0 · EC 1.5–2.5 · Temp 55–70°F
Vegetables

How to Grow Zucchini Hydroponically

Dutch Bucket setup, hand pollination of male/female flowers, blossom end rot prevention.

pH 5.5–6.5 · EC 1.8–3.0 · DLI 20–30
Vegetables

How to Grow Eggplant Hydroponically

Long-season warm-weather crop, fruiting EC targets, variety comparison, pruning for yield.

pH 5.5–6.5 · EC 2.0–3.5 · Temp 75–85°F
Vegetables

How to Grow Bok Choy Hydroponically

Fast brassica for NFT and raft systems. Bolt prevention, tip burn fix, baby vs full-size targets.

pH 6.0–7.0 · EC 1.2–2.0 · Harvest 30–70 days
Fruits

How to Grow Strawberries Hydroponically

Day-neutral varieties, vertical tower systems, hand pollination, chilling requirements.

pH 5.5–6.5 · EC 1.2–2.0 · DLI 15–25

Herb Grow Guides

Herbs

How to Grow Basil Hydroponically

Heat-loving herb with fast yields. Pruning to prevent bolting, variety comparison, DWC targets.

pH 5.5–6.5 · EC 1.0–2.5 · Temp 70–85°F
Herbs

How to Grow Mint Hydroponically

Propagation from cuttings, preventing flowering for maximum leaf yield, variety guide.

pH 6.0–7.0 · EC 1.4–2.2 · DLI 10–16
Herbs

How to Grow Cilantro Hydroponically

Solve the bolting challenge. Seed splitting technique, succession planting, slow-bolt varieties.

pH 6.0–6.7 · EC 1.2–1.8 · Temp 50–70°F
Herbs

How to Grow Chives Hydroponically

Division propagation, monthly harvests, garlic vs common chives, DWC and NFT targets.

pH 6.0–7.0 · EC 1.4–2.2 · DLI 10–16
Herbs

How to Grow Parsley Hydroponically

Overcome slow germination (14–28 days), flat-leaf vs curly comparison, continuous harvest method.

pH 6.0–7.0 · EC 1.2–2.5 · DLI 10–16
Herbs

How to Grow Green Onions Hydroponically

Regrow from kitchen scraps in 10 days. Seed-to-harvest guide, succession planting, variety guide.

pH 6.0–7.0 · EC 1.4–2.2 · DLI 10–16
Herbs

How to Grow Watercress Hydroponically

Aquatic plant that thrives in DWC. Higher pH targets (6.5–7.5), iron needs, store-bought propagation.

pH 6.5–7.5 · EC 0.8–1.8 · Temp 50–68°F
Herbs

How to Grow Celery Hydroponically

Regrow from store-bought base. Calcium blackheart prevention, boron needs, blanching technique.

pH 6.0–7.0 · EC 1.8–3.0 · DLI 14–20
Microgreens

How to Grow Microgreens Hydroponically

Harvest in 7–21 days. Mold prevention, blackout method, top 10 variety guide with exact harvest times.

pH 5.5–6.5 · EC 0.8–1.6 · Harvest 7–21 days

Equipment Guides

Equipment

LED Grow Lights Guide — PPFD, DLI & Spectrum

How to choose the right LED for your grow tent. PPFD charts, DLI calculator, spectrum explained.

PPFD · DLI · Spectrum · Quantum Board · Bar LED
Equipment

Grow Tent Setup Guide — Complete Build Checklist

Everything you need in your first grow tent. Sizing, ventilation, lighting, and environment setup.

2×2 · 4×4 · 4×8 · Fan · Filter · LED
Equipment

Grow Room Ventilation Guide — CFM, Fans & Filters

Calculate the right CFM for your space. Inline fans, carbon filters, negative pressure, ducting.

CFM Calculator · Inline Fan · Carbon Filter · Duct
Equipment

Hydroponic Nutrients Guide — NPK, EC & Schedules

Macronutrients, micronutrients, EC/PPM targets, pH interaction, and deficiency diagnosis.

NPK · EC · PPM · pH · Deficiency · Feeding Schedule
Equipment

DWC Hydroponic Guide — Deep Water Culture Setup

Complete DWC build guide. pH & EC targets, root rot prevention, air pump sizing, and nutrient schedule.

DWC · Deep Water Culture · Root Rot · Air Pump · EC
Equipment

Quantum Board Grow Light Guide

Samsung LM301B/H chips, PPFD targets, wattage by tent size, dimming, and top brand comparison.

Quantum Board · PPFD · DLI · HLG · Mars Hydro · Spider Farmer
Equipment

Grow Tent Sizes Guide — 2×2 to 10×10 Chart

Complete size comparison chart for every standard tent. Plant counts, LED wattage, CFM fan sizing by size.

2×2 · 3×3 · 4×4 · 4×8 · 5×5 · 8×8 · 10×10

Free Tools

Tool

VPD Calculator — Vapor Pressure Deficit

Enter temperature and humidity to instantly calculate VPD. Color-coded targets for every grow stage.

VPD · Leaf VPD · Heatmap · Stage Targets
Tool

EC to PPM Calculator

Convert EC to PPM (500 or 700 scale) instantly. Includes nutrient target charts for every plant and stage.

EC · PPM · TDS · 500 Scale · 700 Scale
Tool

Best Grow Room Monitor — GrowAI Review

7-parameter monitoring: VPD, temp, RH, CO₂, DLI, pH, EC. USA, Canada & UK availability.

Monitor · VPD · CO₂ · pH · EC · USA · UK · CA