Hydroponics & Indoor Gardening Learning Center


Urban Growth is a San Diego nonprofit organization dedicated to promoting sustainable farming. They offer educational programs for youth, adults, and communities. Also at Instagram and Facebook

Here's a good article for beginners to hydroponics discussing different types of systems and how they work.

Hydroponics, gardening without soil. Article about hydroponics and four different types of systems.

Here's a definition of Rockwool and description of the different products used for hydroponics.

How to build a typical ebb and flow tray system.

Details about our popular Multi Flow Hydroponic System.

Instructions for the Multi Flow System. Perhaps the best hydroponic system ever made. ;) And a sales flier.

Frequently asked questions page about hydroponics and indoor gardening.

Hydroponic Nutrient

Flora Nutrient Weekly Feeding Calculator. Use this to create a table you can use from beginning to end.

Nutrient strength is measured in parts per million (PPM) and electrical conductivity (EC). Learn why you should know the difference

To find the N-P-K ratio for a blend of the three Flora nutrients use the Flora Nutrient Calculator

Basic nutrient deficiencies table. With a list of elements that may be the suspect.

Flora Nutrient Mixing Rates for some popular hydro crops.

Flora Nutrient Guaranteed Minimum Analysis. Details of each element in the Flora Nutrient.

One of many mixing ratios for the General Hydro Flora Nutrient.

Symptoms of deficiencies and toxicities for the 13 elements found in hydroponic nutrient.

Indoor Gardening

Controlling heat in the grow room is very important. This article will give you an idea of how it's done.

How to take and root cuttings (clones). This is probably the hardest part to master.

Specifications for the exhaust blowers including wattage and air flow.

Indoor gardening and the environmental issues you will face.

Here is a CO2 calculator that will tell you how long a carbon dioxide tank will last.

Grow Lights

A page about the different types of grow lights and how to select one.

Here's a page about the different types of lights that can be used for growing.

Do you want to run you lights on 220 volts to save power? If so, you should read this first. Watts cheaper 110 or 220?

A definition of CRI, Color Temperature and Lumens for high intensity discharge lights.

The basic information on how to choose a grow light

Calculator for finding the cost to operate a grow light and the bulb replacement cost.

Compare prices and basic features of our most popular light systems

HID Ballast Guide from Advance transformer. Includes specifications and lamp types. 68 page file.

Hydroponics Manufacturers & Distributors

Botanicare manufactures many hydroponic systems and nutrient formulas.

Grodan is the manufacturer of the most popular rockwool for hydroponics. The hobby grower website is here

General Hydroponics is best know for their nutrient. They make the AeroFlo, WaterFarm & RainForest systems. Many of their products are listed on our site.

Hawthorne Gardening Company is probably the most widely known hydro distributor with thousands of products.

High Intensity Discharge (HID) Lighting Manufacturers

Sunmaster makes high output lamps for the hydroponics industry.

Universal Lighting Technologies Another ballast manufacturer.

Sylvania Our preferred manufacturer for lamps. Very reliable bulbs.

Philips Another lamp manufacturer.

Other Helpful Links

GardenGuides is a well-recognized gardening resource for flower, herb and vegetable gardeners containing over 400 original articles.

Need to find out how many ounces are in 600 teaspoons? Try Online Conversion Convert just about anything to anything else.

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