Hydrobuilder Learning Center
Grow guides from people who actually grow.
Step-by-step guides, calculators and fixes for hydroponic, indoor and greenhouse growers, from your first tent to a commercial facility.
Start here if you’re new
Hydroponics 101: The Complete Beginner’s Guide to Growing Without Soil
You are probably excited to learn how to grow hydroponics plants. We’ve got a lot to cover before…
Growing in Coco Coir: The Complete Setup & Feeding Guide
Growing in coco coir gives indoor growers precise control over aeration, moisture retention, and nutrition — but getting…
Grow Light Coverage Calculator: How Many Grow Lights Do You Need?
Calculating your grow lighting requirements really is just two steps – determine your plant’s lighting needs (watts/square foot),…
Harvest, Drying & Curing: Beginner’s Complete Guide
Learn how to harvest, dry, and cure cannabis the right way. This beginner's guide covers trichome timing, wet…
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Hydroponics
System types, reservoirs, grow guides
Pest Control
Bugs, illnesses, IPM techniques
Nutrients & Fertilizer
Basics, supplements, deficiencies
Grow Lights
LED, CMH, HPS, coverage
Environment
Humidity, heat, ventilation
Harvest
Trimming, drying, curing, storage
Plant Grow Guides
Vegetables, fruits, herbs, flowers
Commercial & Automation
Facilities, automation, benching
Most read right now
Trimming & Bucking
Dustin Davis
Wet Trim vs Dry Trim: Methods, Machines & Hand Trimming Guide
Wet trimming keeps trichomes intact and less fragile during the cutting process — they're still supple and adhere well. But the faster drying that follows a…
Dustin Davis
Best Trimming Machines for Every Grow Size
Trimming & Bucking · Dustin Davis
Vapor Pressure Deficit (VPD) Calculator & Chart for Cannabis and Indoor Growing
Humidity & Temperature · Dustin DavisHow to Mix Plant Nutrients: Order, Ratios & Avoiding Lockout
Plant Nutrition Basics · Dustin DavisIndoor Grow Room Design & Setup Examples
Grow Room Design · Dustin DavisGrow Room & Grow Tent Ventilation Setup: The Complete Guide
Ventilation, Odor & CO2 · Dustin Davis
Grower calculators
All 18 tools →Grow Light Coverage
Fixtures needed for your footprint and target intensity.
VPD Calculator
Dial temperature and humidity for each stage.
CO₂ Flow Rate
Regulator flow for your room volume.
EC to PPM Converter
Switch between meter scales without the math.
New guides
Supplements & AdditivesGarrett Dupree
Wetting Agent for Plants: Foliar Sprays vs Growing Media
Wetting agents solve two different problems: sprays that bead up on waxy leaves and dry peat mixes that shed water. Learn how surfactants work, when a…
Garrett Dupree
Grow LightsGarrett Dupree
Grow Room Glasses: Pick the Lens for Your Light, Then Check the Rating
Not every “LED” lens suits every LED. Learn how to match grow room glasses to full-spectrum LED, blurple LED, HPS or mixed lighting, what color correction…
Garrett Dupree
Grow LightsGarrett Dupree
Green Grow Room Light Guide: Work Lights and Exit Signs
Green light helps you see during the dark period, but plants aren’t blind to it. Learn what the research says about green light and flowering, how…
Garrett Dupree
Pest Control TechniquesGarrett Dupree
Jeweler’s Loupe for Plants: What Power to Buy and How to Scout With It
Use a jeweler’s loupe or digital microscope to spot mites, thrips and mildew early. Learn which magnification you need and how to scout plants weekly.
Garrett Dupree
Grow Diagnostics
Stop guessing what’s wrong with your plants.
Send a tissue or media sample and get a lab report with a plain-English action plan from our grow team.
See how testing works
Written by growers
Dustin Davis
Harvest & curing, Coco coir, Grow lights
Jacob Rodowick
Hydroponics, Grow systems, Cultivation tech
Garrett Dupree
Vegetables, Food crops, Garden care
Tyler Hair
Mushrooms, Specialty crops