Kratky hydroponic method using one-gallon ($1) container for lettuce, parsley, etc.

The Kratky Method of Non-circulation, non-electric hydroponic system was developed by Prof. Kratky from University of Hawaii. It works best for growing lettuce. You only need to fill the hydroponic container once during the grow cycle, when the planting the lettuce. No pump or aeration is needed. The most complete and practical description of the method is available in PDF form here:

Buttercrunch lettuce in Kratky hydroponics at the time of transplant to a net cup:

Lettuce grown with Kratky hydroponics, after 1 month:

Containers for Kratky hydroponics can be made from a variety of sources: Note the 2-inch hole for a net cup in the top cover of the containers, and black spray paint or aluminum foil that blocks the light from entering the water/fertilizer chamber:

You will need:

- one plastic gallon container with a lid
- black trash bag for lining the container. Alternatively, you can use black spray pain to paint the container, or you can wrap it in aluminum folio.
- 2-inch net pots
- mix of peat moss/coconut coir and perlite/vermiculite
- hydroponic fertilizer
- CFL daylight bulbs (if growing inside) and 15-inch desk lamp
- vegetables seeds
- plastic tray for germination
- 3/8 drill and 2-inch hole saw and mandrel

Fill the net pots with the mix and place in the plastic tray. Moisten the mix. Plant the seeds. After the seedlings have their first true leaves, assemble the hydroponic setup (see the PDF above). Make sure the net pots a submerged by 1/4 inch in the hydroponic fertilizer.

The containers are often available in Dollar Tree for $1.

Most of the the supplies for this setup are available from

A suitable spray paint is Rust-Oleum Paint Plus 12-oz. 2x Spray Gloss Black ($3.40 at Home Depot). It attaches to plastic and glass and does not require a primer.

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