So then. Aquaponics. I’d assumed it was something to do with growing underwater plants. Dead wrong.

My educative moment occurred at Disneyworld’s Epcot a couple of years ago. There’s a ride called The Land, where, after enduring a selection of creaking dioramas illustrating different US habitats, you’re taken on a little motorised punt thing on a watery track through greenhouses groaning under the weight of four-kilogramme mega-lemons, arboreal tomatoes and Mickey-shaped pumpkins.

Giant lemon, from Arild Finne Nybø on Flickr.

At the end of the…river thing…, you’ll find a section on aquaponics. An aquaponics system creates an incredibly efficient symbiotic environment for raising food. Aquatic food (prawns, fish and the like) is raised in water. Waste products from those creatures, which in an aquatic-only environment would degrade the quality of the water, are diverted into a hydroponic system, where nitrogen-fixing bacteria turn them into nitrates and nitrites, which are used to feed edible plants. The water can then be recirculated into the fish tank.

Finesse is required. You need to be able to monitor and control temperature, drainage and pumping. Professional systems are expensive, so the enterprising aquaponics practitioner will want to build their own. Enter the Raspberry Pi. And a shipping container, a shed and some valves.

MatthewH415, the maker, has documented the whole build at Instructables. He says:

This build uses the IBC method of Aquaponics, with modifications to include a Raspberry Pi for controlling a pump, solenoid drain, and temperature probes for water and air temperatures. The relays and timing is controlled with python scripting. Temperature and control data is collected every minute and sent to plot.ly for graphing, and future expansion will include sensors for water level and PH values for additional control.

All of my scripts are available at github.com, feel free to use them for your aquaponics setup. Thanks to Chris @ plot.ly for the help with streaming data to their service, and to the amazingly detailed build instructions provided at IBCofAquaponics.com.

We love it. Thanks Matthew; come the apocalypse, we at Pi Towers are happy in the safe and secure knowledge that we’ll at least have tilapia and cucumbers.