Aquaponics in Ontario: The Honest Guide to Fish, Plants, Heat and the Room They Live In

Reading Time: 14 minutes

What Aquaponics Is, and What It Is Not

Aquaponics is the combination of recirculating aquaculture, the growing of fish in tanks, with hydroponics, the growing of plants in water without soil, in one loop. The Rutgers cooperative extension fact sheet FS1351 defines it that way and explains the chemistry that makes it work: fish excrete ammonia, which is toxic to them; bacteria living on surfaces in the system convert the ammonia to nitrite and then to nitrate, which is far less toxic to fish and is the form of nitrogen plant roots take up easily; the plants strip the nitrate from the water, and the cleaned water returns to the fish. The bacteria are the third crop, and a new system spends its first weeks growing them before it grows anything else.

Two things aquaponics is often mistaken for: a garden that feeds itself, and hydroponics with a fish tank bolted on. It is neither. Hydroponics doses plants with a mixed nutrient solution and controls every variable; aquaponics runs a living balance in which the fish feed rate sets the nutrient supply and every parameter, temperature, pH, dissolved oxygen, has to suit fish, plants and bacteria at once. That is why that guide and this page describe different projects, and why the honest answer to “aquaponics or hydroponics” for a first indoor farm in Ontario is usually hydroponics unless the fish are the point.

The Three System Types, Decoded

Two design rules follow from the table and from Clemson’s system-layout guide. Solids have to leave the water quickly, ideally by settling in a clarifier straight after the fish tank, because solids left in the system feed bacteria that consume the oxygen the fish need. And the biofilter, wherever it lives, needs enough water flow to deliver the dissolved waste, enough surface area for the nitrifying bacteria to colonize, and oxygen dispersed through the whole filter, which Clemson puts at a minimum of six milligrams per litre. A media bed does both jobs in one box, which is why it is the beginner’s system; a raft system separates them, which is why it scales.

Trout or Tilapia: The Ontario Decision

The fish decides the water temperature, and the water temperature decides the heating or chilling bill, which in Ontario is the largest operating line after light. The two species that dominate the category sit at opposite ends of the thermometer.

Read the table against the calendar. Tilapia is the textbook aquaponics fish because it is hardy, fast-growing and tolerant of crowding, and it is a tropical fish; an Ontario tilapia system is a heated system for eight months of the year. Trout is the fish the province’s own climate suits, and the plants have to agree: lettuce, herbs and brassicas grow well in cool water, while tomatoes and basil want the warmth tilapia wants. Culturing fish in Ontario needs a provincial aquaculture licence, so confirm the rules and the permitted species with the province before you stock. Rutgers lists tilapia, koi, catfish, goldfish and ornamentals as the common choices in its own climate; the cold-water route is the Ontario addition.

The Numbers That Size a System

Three published figures do most of the sizing work, and they are the ones to design from rather than around. Rutgers’ stocking rule is ten gallons of water for every pound of fish at market size, so a 500-gallon tank carries about fifty pounds of fish at harvest, which is the number that then sets the feed rate, and the feed rate sets how much plant area the system can support. Dissolved oxygen in the fish tank should sit as close as possible to seven or eight parts per million, per the same sheet, which is what the aeration is sized to hold on the warmest day, because warm water holds less oxygen and tilapia water is warm. And the biofilter needs at least six milligrams per litre of oxygen dispersed through it, per Clemson, which is why the air pump and the water pump are the two components no one should economize on.

The fourth number is weight, and it matters for the envelope more than for the biology. Water weighs about 8.3 pounds per US gallon, so that 500-gallon tank is more than two tons before the fish, the media and the rafts are counted. On a basement slab that is a non-issue; on a raised floor, a trailer or a container it is the first question, and the container section below answers it.

The Disadvantages, From the People Who Teach It

Google’s first question under the word is what the disadvantages are, and the extension sheets answer it plainly. Rutgers lists a higher level of technical expertise than a garden or a hydroponic bed, because three organisms have to be kept happy at once; a higher energy bill, for pumps, lighting and heating or cooling; vulnerability to power outages, which the sheet calls catastrophic to the fish and the plants, since a stopped pump means falling oxygen within hours; time-intensive water quality monitoring; a limited crop list, because the plants that thrive on nitrate at fish-friendly temperatures are mostly greens and herbs; and licensing for the fish. Add the Ontario winter to that list and the honest summary is that aquaponics is a rewarding, technical, indoor, powered system rather than a low-effort one, and anyone selling it as self-sustaining is selling.

The Ontario Problem: Heat, Light and Power

Three things the reference sheets written for New Jersey and South Carolina do not have to say. Heat: a system is a body of water at a set temperature inside a room at a set temperature, and from November to March both are fighting the outdoors, so the envelope’s insulation is an operating cost every month it runs; the container greenhouse cost guide calls HVAC the biggest cost in any container grow and it is truer with a fish tank in the room. Light: an Ontario winter delivers a fraction of the daily light a leafy crop wants, so any indoor system runs LEDs on a photoperiod, and the supplemental lighting guide works out the wattage and the circuit. Power: the outage the extension sheet calls catastrophic happens here in an ice storm, so a battery-backed air pump at minimum and a generator transfer switch for a commercial system are part of the design, not an option, and the 60-amp versus 100-amp service guide is the read for what the panel needs to carry.

Basement, Greenhouse, Barn or Container

The table is the honest version of where a container belongs in this story: late, and as one of four. A hobby system belongs in a basement or a heated garage. A commercial greens operation with fish belongs in a purpose-built room, and a container is a purpose-built room that arrives on a truck, which is why the hydroponic container farm is an established category and an aquaponic one is a variation on it rather than a new idea. The microgreens container farm guide is the lightest version of the same room.

The Container Build, Done Properly

Start with the shell. The 40-foot high cube is the standard for any container grow because its nine-foot-six interior clears vertical racks, overhead lights and the ducting, and its 320 square feet is a single-car garage’s worth of floor; a 20-foot unit is the hobby or school version at 160. Buy it one-trip, because every wall will be cut, lined and sealed and straight steel makes that work cleaner, and because a used floor under two tons of water is a floor you want to know the history of. The grade breakdown explains why.

Then the floor, which is the aquaponics-specific problem. A container floor is marine plywood over steel cross-members, rated for a distributed cargo load far past anything a grow room will carry, but a round tank puts its weight in one place. The fix is the one every fish-tank builder uses: set tanks on a spreader of doubled plywood or a steel frame that lands the load across several cross-members, keep the heaviest tanks toward the container’s ends where the structure is stiffest, and put a floor drain and a sealed, sloped membrane floor in before anything else, because a spill in a steel box goes to the lowest corner and stays there. The flooring guide covers what is under the plywood, and a well-built gravel pad, level, is what the container itself should sit on.

Then the envelope. Closed-cell spray foam on the inside of the steel is the insulation answer for a heated, humid room, because it is the vapour barrier and the insulation in one pass and it leaves no cavity for condensation to collect against cold corten; the passive-versus-mechanical ventilation comparison explains why a sealed steel box has to be ventilated mechanically and, with a fish tank, dehumidified. Line the walls with a washable panel, run the electrical in sealed conduit to a panel sized for pumps, lights, heat and a dehumidifier, and put the backup for the air pump on its own circuit. Openings, a personnel door and a louvre or two, are cut and framed at our shop in Brantford before delivery, and the conversions overview shows the kind of work involved.

What the container gives back is the thing the other three envelopes struggle with: a sealed, insulated, lockable room whose climate is entirely yours, set down on a pad beside a barn, a school or a restaurant in an afternoon, and lifted onto a truck if the business moves. The worm farm container guide and the on-farm storage guide are the same box doing neighbouring jobs on the same property.

Who Should Build One, and Who Should Not

Build an aquaponics system if the fish are part of the point: a school teaching the nitrogen cycle with a living example, a hobbyist with a heated space who wants trout and lettuce from the same water, a small grower with a market for both greens and fish and the technical patience the extension sheets describe. Build it in whichever envelope you already have that is heated, strong-floored and powered; buy a container for it when you need a room that does not exist yet, or one that has to be sealed, lockable and movable.

Do not build one to save money on lettuce, because a hydroponic bed grows the lettuce with fewer variables, and do not build one anywhere the power can go out without a backup. And if the job is really a grow room without fish, the hydroponic container guide is the page to read instead; the box is the same, the biology is simpler, and the greenhouse guide covers the payback arithmetic that a fish tank complicates.

The Container You Would Buy

For the grower who has decided the envelope is a container, the yard’s answer is the high-cube forty, one-trip, from the new one-trip inventory: 320 square feet, nine-foot-six inside, straight walls for the foam and the panels, a sound floor for the spreaders and the drain. A school or hobby system fits a 20-foot standard box. Used wind-and-watertight units from the second-hand stock are the answer for the storage and the feed room beside the grow container rather than for the grow container itself.

Every container we sell is picked by a person and can be picked by you: drive to 90 Morton Avenue East, walk the rows with Paul or Christian, and choose the shell by its number and its floor before any money moves. Payment is on delivery, after you have seen the box on your ground. Delivery is by tilt-deck in one to three days to every corner of Ontario we serve, the delivery-day sequence is shown step by step, and our site-prep notes cover the pad, the power run and the drain. Whether a grow container can sit on a given lot is your municipality’s call, so check with your local planning department before you order. The quote drivers are on their own page. Everything is sold outright; Van Blanc keeps no rental fleet and does not lease.

For the wider picture of what kind of building a growing operation needs, the building-type comparison is the read, and Guelph, home of the province’s agricultural university, is where a good share of these calls come from.

Reach Van Blanc in Brantford

We have been supplying shipping containers across Ontario since 1995. Our yard is at 90 Morton Avenue East in Brantford, and we deliver right across the province with payment on the day of delivery. No deposit, no upfront wires, no chase-the-paperwork.

Van Blanc Ent. Inc., 90 Morton Ave E Unit 1B, Brantford, ON N3R 7J7, 519-754-6844 (cell) or 1-888-509-6658 (toll-free).

If the system is designed and the next question is the room it lives in, call with the size, the tank plan and your postal code and we will tell you on the spot what one-trip high cubes are in stock and when one can land. Worth the drive for unbeatable quality, family customer service with 30 years of experience.

Related Reading

• Hydroponic Shipping Container Grow in Ontario
• Container Greenhouses in Ontario
• Container Greenhouse Cost and Build in Canada
• Supplemental Lighting for Container Greenhouses
• Microgreens Vertical Farm Container in Ontario