Aquaponics and IBC Totes: The Perfect Partnership for Urban Farming

What Is Aquaponics?

Aquaponics is a food production system that combines aquaculture (raising fish) with hydroponics (growing plants without soil) in a symbiotic closed-loop environment. In an aquaponics system, fish produce waste that contains ammonia. Beneficial bacteria convert this ammonia first into nitrites and then into nitrates, which serve as natural fertilizer for the plants. The plants absorb these nutrients, cleaning the water, which then recirculates back to the fish tank. The result is a self-sustaining ecosystem that produces both protein (fish) and produce (vegetables and herbs) with minimal external inputs.

Aquaponics has exploded in popularity over the past decade, driven by growing interest in local food production, urban farming, sustainability, and food security. And at the center of the DIY aquaponics movement is the humble IBC tote, which turns out to be an almost perfect building block for home and community-scale aquaponics systems.

Why IBC Totes Are Ideal for Aquaponics

There are many reasons why the IBC tote has become the standard container for DIY aquaponics. Here are the key advantages:

Food-safe material: Food-grade IBC totes are made from HDPE that is FDA-compliant for food contact. This is essential for a system that produces food. The plastic will not leach harmful chemicals into the water that could harm the fish or contaminate the produce.
Ideal size: The 275-gallon capacity is perfect for a backyard or garage aquaponics system. It provides enough water volume to maintain stable water chemistry (larger volumes are more forgiving of temperature and pH fluctuations) while still being manageable for a single person or small team to set up.
Built-in drainage: The bottom valve on an IBC tote makes plumbing connections easy. You can use the existing valve port for water circulation without cutting additional holes.
Structural support: The steel cage provides a rigid frame that supports the weight of the water (over 2,000 pounds) and also serves as a mounting structure for grow beds, piping, and accessories.
Stackable design: The cage and pallet design allows one IBC to support weight on top. This is the foundation of the classic IBC aquaponics design where a cut-off portion of the tote sits on top as the grow bed.
Affordable: A used, cleaned, food-grade IBC tote costs $75 to $150, a fraction of the price of purpose-built aquaponics tanks.
Readily available: Used IBCs are easy to find in most metropolitan areas, including right here in Minneapolis.

System Design with IBC Totes

The most popular IBC aquaponics design uses a single tote cut into two sections: a fish tank and a grow bed. Here is the standard approach:

The Basic One-Tote System

Take one IBC tote and cut the top portion off, roughly the top one-third (about 12 inches deep). This cut piece, inverted, becomes the grow bed. The bottom two-thirds of the tote, still in the cage and on the pallet, becomes the fish tank. The grow bed sits on top of the fish tank, supported by the cage frame. Water is pumped from the fish tank up to the grow bed, flows through the growing media, and drains back into the fish tank by gravity.

This design is elegant in its simplicity and gives you approximately 180 to 200 gallons of fish tank volume and a grow bed of roughly 4 feet by 3.5 feet with 12 inches of media depth. This is enough to grow a substantial amount of food.

The Expanded Two-Tote System

For more growing capacity, use two IBCs. One remains whole as the fish tank (275 gallons), and the second is cut in half horizontally to create two grow beds. The two grow beds can be positioned side by side on a frame at a height that allows gravity return to the fish tank, or they can be stacked using additional framing. This doubles your growing area while maintaining the same fish tank volume.

The CHOP (Constant Height, One Pump) System

A more advanced design adds a sump tank between the fish tank and the grow beds. The sump tank (which can be a third IBC or a smaller container) receives the drain water from the grow beds. A single pump in the sump sends water both to the fish tank (which overflows back to the sump at a constant height) and to the grow beds (which drain by gravity to the sump). This design provides the most stable water levels and allows for easier maintenance, since the pump is in the sump rather than in the fish tank with the fish.

Fish Tank Setup

Setting up the fish tank portion of your IBC aquaponics system involves several important steps:

Light blocking: HDPE IBC totes are translucent, which allows light to penetrate into the fish tank. This promotes algae growth, which is undesirable. Paint the outside of the fish tank portion with a non-toxic, opaque exterior paint, or wrap it with a light-blocking material. Do not paint the inside, as fish may ingest paint particles.
Aeration: Fish need dissolved oxygen to survive. Install an air pump with air stones in the fish tank to provide continuous aeration. A standard aquarium air pump rated for 300 or more gallons is sufficient. For redundancy, consider installing two air pumps on separate circuits.
Water circulation: The pump that moves water to the grow beds also provides circulation in the fish tank, but ensure there are no dead spots where waste accumulates. Position the pump intake and return lines to promote circular flow.
Drain: The existing IBC valve at the bottom can serve as a drain for water changes and cleaning. Install a ball valve for precise flow control if the original butterfly valve is too coarse.
Cover: A cover or screen on top of the fish tank prevents fish from jumping out (some species are notorious jumpers), keeps debris from falling in, and reduces evaporation. A frame with window screen or shade cloth works well.

Grow Bed Conversion

The cut-off top portion of the IBC becomes the grow bed. Here is how to prepare it:

Reinforcement: When you cut the IBC apart, the top section loses the structural support of the cage. Build a simple wooden or metal frame to support the grow bed at the proper height. The frame must support the weight of the media and water, which can be 300 to 500 pounds depending on the media type.
Drain fitting: Install a bulkhead fitting and a bell siphon or standpipe drain in the grow bed. A bell siphon provides automatic flood-and-drain cycling, which is the most effective irrigation method for media-based aquaponics. The siphon floods the grow bed to a set level, then rapidly drains it, providing alternating wet and dry cycles that promote healthy root growth and beneficial bacteria activity.
Growing media: Fill the grow bed with an inert, pH-neutral growing medium. The most common choices are expanded clay pebbles (also known as hydroton or LECA), lava rock, and river gravel. Expanded clay pebbles are the premium choice because they are lightweight, provide excellent drainage and aeration, and are easy on the hands. A 12-inch-deep grow bed requires approximately 4 to 5 cubic feet of media.
Water distribution: The pump delivers water to the grow bed through a pipe that runs across the top of the media. Drill holes along the pipe to distribute water evenly across the grow bed surface. Alternatively, position the inlet at one end and let the water flow through the media to the drain at the other end.

Plumbing the System

The plumbing for an IBC aquaponics system is straightforward but must be done correctly for reliable operation:

Pump: A submersible pump rated for 400 to 800 gallons per hour is appropriate for a one-tote system. You want to turn over the entire fish tank volume at least once per hour. For a two-grow-bed system, size up to 800 to 1,200 GPH to handle the additional flow.
Pipe sizing: Use 3/4-inch or 1-inch PVC pipe for the main pump line. Smaller pipe creates too much head pressure and reduces flow. Use Schedule 40 PVC with solvent-welded fittings for permanent joints and threaded or compression fittings where you need to disassemble for maintenance.
Valves: Install ball valves on both the pump output and the grow bed inlet so you can regulate flow and isolate sections for maintenance.
Overflow protection: Always include an overflow pipe in the fish tank that drains to a safe location. If the grow bed drain clogs, the pump will continue pumping water into the grow bed, which will overflow. An overflow pipe on the fish tank prevents it from running dry. Similarly, an overflow on the grow bed prevents water from flooding over the edge.
Bypass line: A bypass line from the pump back to the fish tank (or sump) allows you to regulate flow to the grow beds without throttling the pump itself, which can shorten pump life.

Cycling the System

Before adding fish, you must cycle the system. Cycling is the process of establishing the beneficial bacteria colonies that convert toxic ammonia into less toxic nitrates. This is the most critical step in setting up an aquaponics system, and rushing it is the most common cause of fish death in new systems.

The fishless cycling process takes approximately four to six weeks and involves the following steps:

Fill the system with dechlorinated water. If your water is chlorinated (as Minneapolis municipal water is), treat it with a dechlorinator or let it sit for 24 to 48 hours to allow the chlorine to dissipate. Chloramine, which is also used in some municipal water systems, does not dissipate and must be chemically neutralized.
Add an ammonia source: Pure ammonia (without surfactants or fragrances) is the standard cycling agent. Add enough to bring the ammonia level to 2 to 4 parts per million (ppm). You can also use fish food: add a small amount daily, and as it decomposes, it releases ammonia.
Test water regularly: Use an aquarium test kit to monitor ammonia, nitrite, and nitrate levels. Initially, ammonia will rise. After one to two weeks, you will see nitrites appear as the first stage of bacteria (Nitrosomonas) begins converting ammonia to nitrite. After another one to two weeks, nitrates will appear as the second stage of bacteria (Nitrospira or Nitrobacter) converts nitrite to nitrate. The cycle is complete when ammonia and nitrite levels drop to zero and nitrates are present.
Maintain temperature: Beneficial bacteria grow most quickly at temperatures between 75°F and 85°F. If cycling in a cold Minnesota garage, use an aquarium heater to maintain temperature in this range during the cycling process.

Suitable Fish and Plants for Minnesota Climate

Choosing the right fish and plants for your climate is essential for a successful aquaponics system:

Fish Species

Tilapia: The most popular aquaponics fish worldwide. Tilapia are hardy, grow quickly, eat almost anything, and taste great. However, they are tropical fish that require water temperatures above 60°F and thrive at 75°F to 85°F. In Minnesota, tilapia can only be raised in heated indoor systems or outdoor systems during summer months.
Bluegill and sunfish: Native to Minnesota, these species are well-adapted to our climate and can tolerate a wider temperature range (50°F to 85°F). They grow more slowly than tilapia but are an excellent choice for unheated garage or outdoor systems that operate primarily in the warmer months.
Channel catfish: Another good option for Minnesota aquaponics. Catfish tolerate temperatures from 50°F to 85°F and grow to edible size in one to two years.
Trout: For cold-water systems, rainbow or brook trout are an option. They prefer temperatures between 55°F and 65°F, making them suitable for systems in cool basements or garages. However, trout are more sensitive to water quality and require higher dissolved oxygen levels.
Goldfish and koi: If you are growing plants for ornamental or non-food purposes, goldfish and koi are extremely hardy, tolerate cold water, and produce ample waste to feed the plants. They are not edible, but they are virtually indestructible.

Plant Choices

Leafy greens: Lettuce, kale, Swiss chard, spinach, and arugula grow exceptionally well in aquaponics and are the easiest plants for beginners. They require moderate nutrient levels and grow quickly.
Herbs: Basil, mint, cilantro, parsley, chives, and oregano thrive in aquaponics grow beds. Fresh herbs are high-value crops that can offset the cost of operating the system.
Tomatoes and peppers: Fruiting plants require higher nutrient levels and a more mature, heavily stocked system. Once your system is established (six months or more), tomatoes and peppers can produce abundantly.
Cucumbers and beans: Vining crops do well in aquaponics with vertical support structures.
Strawberries: A great choice for media-bed aquaponics. Strawberries produce well and are a high-value crop.

Year-Round Indoor Growing in Minnesota

Minnesota's short growing season (typically mid-May through mid-September for outdoor gardens) is one of the strongest arguments for indoor aquaponics. With a properly set up indoor system, you can grow fresh food 365 days a year, regardless of the blizzard raging outside.

Key requirements for year-round indoor aquaponics in Minnesota:

Space: A single-IBC system fits in a footprint of approximately 4 by 5 feet with a height of 5 to 6 feet. A heated basement, garage, spare room, or greenhouse can work.
Lighting: Without natural sunlight, you will need grow lights. Full-spectrum LED grow lights are the most energy-efficient option. Plan for 30 to 50 watts of LED lighting per square foot of grow bed for fruiting plants, or 20 to 30 watts per square foot for leafy greens and herbs.
Heating: Maintain the room temperature above 60°F for tropical fish species, or keep it cooler (50°F to 65°F) if raising cold-water species like trout. An aquarium heater in the fish tank can supplement room heating.
Ventilation: Indoor aquaponics systems produce humidity. Ensure adequate ventilation to prevent mold growth and maintain healthy air exchange for the plants. A small exhaust fan on a humidistat works well.
Electricity: Budget for the operating cost of the pump, air pump, heater, and grow lights. A typical single-IBC indoor system consumes approximately 200 to 400 watts continuously, costing roughly $15 to $30 per month in electricity at Minnesota rates.

Startup Costs

One of the great things about IBC aquaponics is that it is remarkably affordable compared to commercial aquaponics systems. Here is a realistic startup budget for a single-IBC system:

Used food-grade IBC tote: $75 to $150
Submersible pump: $40 to $80
Air pump and air stones: $25 to $50
PVC pipe and fittings: $30 to $50
Growing media (expanded clay pebbles): $60 to $100 for 4 to 5 cubic feet
Bell siphon components: $15 to $25
Water test kit: $25 to $35
Fish (starter stock): $20 to $50
Seeds or starter plants: $10 to $20
Grow lights (if indoor): $80 to $200
Miscellaneous (dechlorinator, fish food, sealant, paint): $30 to $50

Total estimated startup cost: $410 to $810

Compare this to a commercial aquaponics kit of similar capacity, which can cost $2,000 to $5,000, and the value of the DIY IBC approach becomes clear. And because the system produces food, it begins paying for itself from the first harvest.

Getting Started

If you are inspired to build an IBC aquaponics system, start by securing a clean, food-grade IBC tote. This is the foundation of your system, and starting with a quality container is important. At IBC Minneapolis, we always have food-grade totes in stock that are perfect for aquaponics applications. We can help you select the right one and answer any questions about preparing it for your build. Whether you are a seasoned urban farmer or a complete beginner, aquaponics with IBC totes is an incredibly rewarding project that brings fresh, sustainable food production right into your home or backyard.