Talking water conservation with Raincoast Aquaponics

Lauren Frost, Guest Columnist, Cowichan Valley Citizen, August 20 2015

Editor’s note: If you haven’t met “Flo” yet, this superhero is visiting Cowichan communities this summer, helping us face down a severe drought and water restrictions. Cowichan Watershed Board summer student Lauren Frost reports in weekly as Flo visits local watershed heroes to learn more about their work (and snap a selfie)!

Raincoast Aquaponics founder Adrian Southern and water hero Flo.— image credit: SubmittedName: Adrian Southern

Occupation: Owner/Founder, Raincoast Aquaponics

Why Flo likes him/her: Water Conservation Hero

Flo: Hi Adrian. Let’s start with how long you have lived in Cowichan Region.

Adrian: I grew up in Cowichan Bay, and recently moved back here from Nanaimo.

Flo: You stand out as a friend of the watershed because of the efforts you make to save water. Thank you for that! What inspired you to start an aquaponic farm?

Adrian: My hatred of weeding.

Flo: Tell us more about what you do and how it helps conserve Cowichan water.

Adrian: Our aquaponic farm is based on an ancient technique of rotating fish and vegetable crops, combining AQUAculture and hydroPONICS. The fish are grown in culture tanks which are connected to a hydroponic vegetable growing system.

The waste water leaving the fish tanks is circulated through the hydroponic system, where a variety of bacteria work on neutralizing the fish wastes by converting them into minerals and plant nutrients.

The plants in the hydroponic system then absorb the nutrients, effectively cleaning the water, which is then recycled back into the fish tanks.

Raincoast Aquaponics holds around 50,000 liters in the system, but only ‘consumes’ about 200 liters per day. This is to replace water lost to evaporation and cleaning filters. With this amount of water, Raincoast has the capacity to produce a maximum of about 1000 kilograms of rainbow trout, and 60,000 heads of lettuce every year. The reason we use so little water is because we never ever dump our used water and replace it with fresh water, which is typical of hydroponic systems and of land-based fish farms.

In addition to this, we capture all of our wastewater and use it to water field crops beside the greenhouse. This is exactly the same as grey-water capture in a residential household.

Flo: Wow! That is amazing. You grow so much food on far less than one local household’s average daily water use. What an inspiration! If you could ask every Cowichan region resident to do one thing for our watershed, what would it be?

Adrian: Let’s stop wasting grey-water. Most Cowichan Valley resident use over 300 liters per day, excluding Ladysmith and Crofton where the average is closer to 250 liters per day… can you imagine how much of that wasted water could be captured as grey-water, and used to flush toilets and water gardens?

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