Aquaponics — the combination of aquaculture (raising fish) and hydroponics (growing plants in water) — is one of the most elegant sustainable food production systems you can build. And an IBC tote is the perfect foundation for a home-scale aquaponics system. In this guide, we'll walk through the complete build process from a single 275-gallon IBC tote.
How Aquaponics Works
The basic cycle: 1. Fish live in a tank and produce ammonia-rich waste 2. Beneficial bacteria (Nitrosomonas and Nitrobacter) convert ammonia to nitrites, then to nitrates 3. Plants absorb the nitrates as fertilizer, cleaning the water 4. Clean water returns to the fish tank 5. The cycle repeats
It's a closed-loop ecosystem where the fish feed the plants and the plants filter the water for the fish. The only inputs are fish food and occasional water top-offs (to replace evaporation).
What You'll Need
Materials:
Tools:
Step 1: Cut the IBC Tote
The standard IBC aquaponics configuration uses the bottom 2/3 as the fish tank and the top 1/3 (inverted) as the grow bed.
1. Mark a cutting line approximately 15-16 inches from the top of the bottle (inside the cage) 2. Carefully cut through the HDPE bottle using a reciprocating saw — go slowly to keep the cut straight 3. Remove the top section of the bottle from the cage 4. Flip the top section upside down — this becomes your grow bed
The bottom section (still in the cage, still on the pallet) is your fish tank. It holds approximately 150-175 gallons depending on your cut height.
The inverted top section is your grow bed. It sits on top of the fish tank, supported by the cage framework. It holds the growing media and plants.
Step 2: Install Plumbing
Fish tank to grow bed (pump line): 1. Install the submersible pump in the fish tank 2. Run 3/4" PVC pipe from the pump, up the side of the tank, and into the grow bed 3. The pump pushes water from the fish tank up into the grow bed
Grow bed to fish tank (drain — bell siphon): 1. Drill a hole in the bottom of the grow bed for a 1" standpipe 2. Install a bulkhead fitting or uniseal 3. Build or install a bell siphon around the standpipe
A bell siphon is a clever device that creates an automatic flood-and-drain cycle in the grow bed. As the pump fills the grow bed, water rises. When it reaches the siphon trigger height, the siphon activates and rapidly drains the grow bed back to the fish tank. Once drained, the siphon breaks and the cycle starts over. This flood-and-drain cycle is ideal for plant root health — the roots get both water and air exposure.
Step 3: Add Growing Media
Fill the grow bed with expanded clay aggregate (LECA) to a depth of about 10-12 inches. LECA is lightweight, pH-neutral, porous (providing surface area for beneficial bacteria), and doesn't decompose. Rinse it thoroughly before adding to remove dust.
Alternatives include lava rock (heavier but cheaper) and river gravel (heaviest, cheapest, but less surface area for bacteria).
Step 4: Cycle the System
Before adding fish, you need to establish the nitrogen cycle — the bacterial colonies that convert toxic ammonia to plant-friendly nitrates. This process takes 4-6 weeks and is critical for fish survival.
1. Fill the system with dechlorinated water 2. Add a source of ammonia (pure ammonia solution — no surfactants — or fish food) 3. Run the pump 24/7 to circulate water through the grow bed 4. Test water daily for ammonia, nitrites, and nitrates 5. The cycle is complete when: ammonia rises then drops to zero, nitrites rise then drop to zero, and nitrates are present and rising
You can accelerate cycling by adding commercially available nitrifying bacteria or media from an established aquarium.
Step 5: Add Fish
Once the system is cycled, add fish gradually — don't fully stock all at once. Start with 25-50% of your target fish load and add more over several weeks as the bacterial colony scales up.
Good fish choices for Kentucky IBC aquaponics:
Stocking density: A good starting rule is 1 pound of fish per 5-10 gallons of fish tank volume. For a 150-gallon tank, that's 15-30 lbs of fish at maturity.
Step 6: Add Plants
Once fish are established and producing waste, you can plant the grow bed. Almost any vegetable or herb grows well in aquaponics:
Easy starters: Lettuce, basil, mint, chives, kale, Swiss chard, bok choy Intermediate: Tomatoes, peppers, cucumbers, beans (need structural support) Advanced: Watermelon, squash (heavy feeders — need mature, well-stocked system)
Simply push seedlings (remove soil from roots first) into the LECA media. The roots will quickly grow into the wet, nutrient-rich environment.
Maintenance
Daily: Feed fish, visually check system is running (pump, siphon, water level) Weekly: Test water parameters (pH, ammonia, nitrite, nitrate), remove dead plant material Monthly: Clean pump intake filter, check for mineral deposits, top off water Seasonal: Adjust fish feeding rate for temperature, harvest and replant as needed
Why IBC Totes Are Perfect for This
The IBC tote is purpose-built for this application:
This is sustainability in action: a recycled industrial container becomes a food production system that uses 90% less water than traditional gardening, produces both protein and vegetables, and creates zero waste.