About this system
Information about the garden and the datalogger.

ed. note - The real-time data from this project is coming from an indoor winter garden that is just finishing up.  The description below is for this year's outdoor garden will be up and running in the few weeks...

About the outdoor garden

This is my third year doing outdoor hydroponic vegetable gardening here in the Bay Area.  The weather is fantastic and provides for excellent growing conditions.  No wonder this whole area was covered in orchards and farms before Silicon Valley came along.  This garden is small (or large, depending on how much space you have...) and has less than ideal lighting conditions.  It receives direct sunlight during the early to mid afternoon.  The rest of the day it's mostly indirect due to blockage from trees and a building.  I have a limited space of about 70 sq ft.  The performance has still been quite good, with last year's bumper crop of cucumbers from a single large plant, several hundred cherry tomatoes, and more zucchini and sqash than I could use.  This year I'm targeting the following:

2 - 3 of each Campari, Carmello, and Roma tomato
2 - 4 of each Sungold, Supersweet 100, and Sweet Gold cherry tomato
3 different zucchini
1 English cucumber
15 assorted green, yellow, burgundy pole beans

The containers for all but the beans will be 6 gallon HDPE plastic food-grade containers.  The rubbermaid reservoir holds approximately 20 gallons when full.  (I'm planning to separate it into two individual reservoirs with a central partition.)  The nutrient solution is pumped to the buckets with two submersible pumps and returned to the reservoir.  Waterfall effect of the returning water near the pumps provides adequate oxygenation of the solution. The buckets and lids are white and are covered with one layer of horticultural black/white poly sheet to keep out the light and prevent algae growth.

A wooden trellis will be increased in height this year to accomodate the tomato and cucumber vines.

Nutrients supply, fill and flush, and circulation will be handled by the automated controller that is being developed as part of the hmeter project.  Full information on this open-source project can be found at http://hmeter.sf.net.