DIY Hydroponics in a Barrel

DIY a Barrel!

“DIY Hydroponics in a Barrel”  is a follow-up to “DIY Aquaponics in a Barrel”. Both “barrelponics” articles are part of our ongoing series covering DIY barrel-conversion projects.

DIY rainwater catchment systems are our specialty. But once you’ve built a BlueBarrel System™️ (or two, or three!), there are still plenty of other ways to upcycle 55-gallon blue plastic drums. (See our other posts for DIY compost tumblers, floating docks, and even a boat!)

Whether you have limited yard space, are interested in water-conscious growing, or are simply looking for a fun alternative to traditional soil-based gardening, hydroponics—in a blue barrel, of course–may be the project for you!  

hydroponios benefits

image source: Fix Blog

What is Hydroponics?

Hydroponics is a method of cultivating plants without soil. 

A quick refresher on the basics of gardening and agriculture: in addition to sunlight, carbon dioxide, and water, plants rely on soil (air/water/minerals/organic matter) to support root structure and nutrients for growth. 




The process of growing plants in nutrient solutions—water + mineral nutrients—without the use of soil.

 From Greek:  hydro- ‘of water’ + ponos ‘labor’ + -ics


Hydroponics eliminates the need for soil by providing nutrients (mineral and organic) through a growing solution (water + nutrients). Sometimes an inert medium like sand or gravel is utilized to support root structure. Alternatively, a plant may be suspended in a solution without the need for soil-like stabilization.

Hydroponics: variations on a theme

There are various methods under the larger umbrella of hydroponics. Many require a pump, drip lines, and/or an aerator, plus an electricity source to keep these devices going. If you’re looking for a more involved DIY hydroponics project, check out this cool aeroponics in a barrel tutorial (as pictured below).

Instructions for this "aeroponics" lettuce barrel can be found here 

The Kratky method or "plant in a barrel"

These basic barrelponic methods are suited to beginners and expert growers alike. One of the simplest is the Kratky method, named for Bernard Kratky, a researcher at the University of Hawaii. This passive hydroponics approach requires no water circulation (no pumps or electricity), offering a one-and-done approach to feeding and watering the plants. 

Here is a basic rundown of the Kratky method:

  1. Fill a barrel with water (rainwater, if you have it, plants prefer it!).
  2. Add liquid nutrients (such as fish fertilizer).
  3. Place a bare root plant (e.g. a lettuce plug with the soil removed) into the barrel, suspended above the water and with roots touching the water. You can use the existing bungholes (see tomato pic below) or cut a larger reservoir into the top of the barrel for inserting plants. 
tomtoes growing in hydroponics barrel

tomatoes growing in 55-gallon a barrel using the Kratky Method

Check out the “Gardening with Leon” video below for more specific Kratky barrel techniques and nutrient solution recipes. With many resources and videos on DIY hydroponics, we hope this blog inspires you to check them out and start growing from blue barrels!

best plants for hydroponics

image source: Fix Blog


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