Aquaponics combines aquaculture (raising fish) with hydroponics (growing plants in water) in a symbiotic system where fish waste provides fertilizer for plants, and plants filter the water for fish. It is one of the most efficient food production methods available -- using 90% less water than traditional farming while producing both protein and vegetables from the same system.
An IBC tank is the most popular starting platform for backyard aquaponics because it provides everything you need in a single container: a large fish tank (the bottom section), a grow bed (the top section cut off), and a steel cage that supports both. A single 275-gallon IBC tank can produce 50-100 pounds of fish and hundreds of pounds of vegetables per year. This guide walks you through building your first system from start to harvest.
Materials and Tools Required
The beauty of IBC aquaponics is its simplicity. Here is everything you need:
Core Components
- 1x 275-gallon IBC tank (used Grade B is perfect)
- Water pump (400-600 GPH submersible)
- Grow media (expanded clay pebbles or lava rock)
- Bell siphon or timer-controlled drain
- PVC pipe and fittings (1-inch and 2-inch)
- Air pump and air stones for fish tank aeration
Tools and Supplies
- Reciprocating saw or jigsaw (for cutting the IBC)
- Drill with hole saw bits (for bulkhead fittings)
- Bulkhead fittings (2x uniseal or tank adapters)
- Plumber's tape and silicone sealant
- Water test kit (ammonia, nitrite, nitrate, pH)
- Fish and plants (added after cycling -- see below)
Total cost for a complete system (excluding fish and plants): $200-350 using a used IBC tank. A comparable commercial aquaponics kit costs $800-2,000. The IBC approach delivers the same growing capacity at a fraction of the price.
Step-by-Step Build Guide
Step 1: Cut the IBC Tank
The standard IBC aquaponics design uses the top third of the bottle as a grow bed and the bottom two-thirds as a fish tank. Mark a cutting line approximately 16 inches from the top of the bottle. Using a reciprocating saw or jigsaw, cut along this line through the HDPE. The steel cage will need to be cut as well -- use an angle grinder or reciprocating saw with a metal blade.
After cutting, you will have two pieces: a shallow tray (the grow bed) and a deep tank (the fish tank). Flip the grow bed upside down and position it on top of the remaining cage, creating a two-tier system. The cage supports both components and keeps everything stable.
Step 2: Install Plumbing
Drill a hole in the bottom of the grow bed for a bulkhead fitting. This is where water will drain back to the fish tank. Install a bell siphon inside the grow bed -- this elegant device automatically floods and drains the grow bed in cycles, providing oxygen to plant roots. The siphon requires no electricity and works purely through physics.
Connect the water pump (placed in the fish tank) to a pipe that delivers water to the grow bed. A simple 1-inch PVC line with a spray bar distributes water evenly across the grow media. The pump runs continuously, pushing water up to the grow bed, where the bell siphon periodically releases it back to the fish tank.
Step 3: Add Grow Media
Fill the grow bed with 8-12 inches of expanded clay pebbles (hydroton) or lava rock. These media provide surface area for beneficial bacteria to colonize -- the bacteria are the engine of aquaponics, converting toxic fish waste (ammonia) into plant-available nutrients (nitrate). Rinse the media thoroughly before adding to remove dust that would cloud your system.
Step 4: Install Aeration
Fish need dissolved oxygen in the water. Place two or three air stones connected to an aquarium air pump at the bottom of the fish tank. The bubbling action oxygenates the water and creates gentle circulation. Aim for at least 1 watt of air pump power per gallon of fish tank volume. For a 180-gallon fish tank (the bottom section of a 275-gallon IBC), a 200+ watt commercial air pump or two standard aquarium air pumps will suffice.
Step 5: Cycle the System
This is the most critical step, and the one most beginners rush through. Before adding fish, you must establish the nitrogen cycle -- the colony of beneficial bacteria that converts ammonia to nitrite to nitrate. Fill the system with dechlorinated water, add a source of ammonia (fish food, pure ammonia solution, or a piece of raw shrimp), and let the system run for 4-6 weeks while monitoring ammonia, nitrite, and nitrate levels with your test kit.
The cycle is complete when ammonia and nitrite levels drop to zero within 24 hours of adding ammonia, and nitrate levels are rising. At this point, the bacterial colony is established and can handle the waste load from fish. Rushing this step -- adding fish before the cycle is complete -- is the number one cause of fish death in new aquaponics systems.
Best Fish Species for IBC Aquaponics
Tilapia (Recommended for Beginners)
Hardy, fast-growing, tolerate wide temperature and pH ranges. Reach plate size (1-1.5 lbs) in 6-9 months. Thrive in the warm water conditions of a well-managed IBC system. Require water temperatures above 60 degrees Fahrenheit -- in Nebraska, this means indoor or greenhouse systems for year-round operation.
Bluegill and Perch
Native to Nebraska and tolerant of cooler water. Better suited for unheated outdoor systems in the Midwest. Slower growing than tilapia but excellent flavor. Can overwinter in an IBC system if protected from freezing (see our winterization guide).
Channel Catfish
Another native species well-suited for Midwest aquaponics. Tolerate a wide range of water conditions and temperatures. Fast growers that produce excellent waste output for plant nutrition. One downside: they can be aggressive, so stock density must be managed carefully.
Goldfish or Koi (Non-Edible)
If you want plants but not fish for the table, ornamental goldfish or koi produce plenty of waste to fertilize the grow bed without the complexity of managing edible fish. They are extremely hardy, cold-tolerant, and inexpensive. A great option for learning aquaponics basics.
Stocking density for a 180-gallon fish tank (the bottom section of a 275-gallon IBC): 20-30 tilapia fingerlings or equivalent biomass. Start with fewer fish and increase as your biological filter matures. Overstocking is the second most common cause of system failure after incomplete cycling.
Best Plants for IBC Aquaponics
Almost any vegetable or herb that grows in soil will thrive in aquaponics, often growing 2-3 times faster due to the constant supply of nutrients and water. Here are the top performers:
Leafy greens (easiest): Lettuce, kale, Swiss chard, spinach, and bok choy are the easiest crops to grow in aquaponics. They have low nutrient demands, grow quickly, and produce continuous harvests. A single IBC grow bed can produce enough salad greens for a family year-round.
Herbs: Basil, cilantro, parsley, mint, and chives do exceptionally well. Basil in particular grows prolifically in aquaponics -- a single plant can produce enough basil for a household with surplus for drying or sharing.
Fruiting plants (intermediate): Tomatoes, peppers, cucumbers, and beans can be grown in a mature aquaponics system with established nutrient levels. They require more light and nutrients than leafy greens, so add them after your system has been running for 3-6 months and nitrate levels are consistently high (40-80 ppm).
Root vegetables (advanced): Carrots, beets, and radishes can grow in deep grow beds with fine media. They require careful attention to media moisture levels and are best attempted after you have experience with simpler crops.
Ongoing Maintenance
Daily (5 minutes): Feed fish. Check water temperature. Observe fish behavior for signs of stress. Verify pump is running and water is flowing to the grow bed. Harvest any ripe produce.
Weekly (20 minutes): Test water parameters (ammonia, nitrite, nitrate, pH). Top off water to replace evaporation and plant uptake -- a 275-gallon system typically loses 5-10 gallons per week to evaporation. Clean any debris from the pump intake screen.
Monthly (30 minutes): Inspect plumbing connections for leaks. Clean the air stones (mineral buildup reduces airflow). Remove any dead plant material from the grow bed. Check the bell siphon for proper cycling. Inspect the IBC for any wear or damage.
Seasonally: Adjust fish feeding rates for temperature changes. In Nebraska, outdoor systems need heating or insulation in winter and possibly shade in summer when water temperatures can rise above 85 degrees Fahrenheit.
Choosing the Right IBC for Aquaponics
For aquaponics, a used Grade B or C IBC tote is ideal. Since you will be cutting the tank apart, cosmetic condition is irrelevant. What matters is structural integrity of the HDPE (no cracks, adequate wall thickness) and a sound steel cage (no broken members). The valve is actually a bonus for aquaponics -- you can use it as a drain for water changes.
Important: If you plan to raise edible fish, use a tank with a known, non-toxic previous contents history. Tanks that previously held food-grade products (juice, syrup, cooking oil) are safe. Tanks that held industrial chemicals should be thoroughly cleaned and flushed multiple times before use with fish. When in doubt, ask us about the contents history of any tank you are considering. Our food-grade vs. industrial guide explains the distinctions in detail.
The 275-gallon size is the standard for aquaponics, but the 110-gallon IBC makes an excellent starter system for those with limited space. The smaller tank produces less food but is easier to manage and fits in smaller greenhouses or even large garages.