What Is iAVs?
iAVs stands for Integrated Aqua-Vegeculture System. It is a method of raising fish and growing vegetables together in one recirculating setup, with sand as the growing medium. iAVs is a soil-based method: the sand bed becomes a living soil, not an inert hydroponic medium, and iAVs is not aquaponics or hydroponics.
How It Works
Water from the fish tank is pumped intermittently (8 cycles, daytime only) into a sand biofilter shaped with ridges and furrows. Solid fish waste is mechanically trapped in the furrows, where microbes mineralize it into plant-available nutrients. The water drains back to the fish tank, with each pass reducing ammonia by ~50%1. The system is chemically self-regulating, stabilizing at pH 6.0–6.5 during active plant growth2.
The water pump runs approximately 2 hours total per day, using roughly 92% less energy than continuous-flow aquaculture systems.
How This Works in Practice
The horticulture dominates your daily attention: planting, pruning, training, pollination, pest management, disease management, crop timing, harvesting, cultivar selection, facility sanitation, and staggered crop rotations. For all of these tasks, you use standard horticultural guidance – there is no need for special iAVs-specific instructions for routine plant care.
The aquaculture is simple: feed the fish twice daily (~6 am and ~1 pm, no feed after 2 pm), only what they consume in 15 minutes. Monitor daily feed consumption; Observe their behaviour and feeding response – these are the most immediate indicators of aquatic health. For basic fish care, use standard species-specific aquaculture guidance.
The system checks are minimal: ensure pumps and timers are working, perform regular water testing, and confirm the 8 daily irrigation cycles are occurring. Ensure proper sanitation and pest control strategies.
What You Need
Core module: A standard unit is a 1,000 L fish tank paired with 6 m² of sand biofilter at a 1:2 volume ratio and 1:6 volume-to-area ratio.
- Fish tank: Rectangular (top view) with rounded corners and a catenary-shaped bottom – flat bottoms should not be used. A pump intake at the lowest point, air stones along the sides.
- Biofilter: A container or excavated bed, sloped bottom (1:50 gradient), minimum 30 cm sand depth, and an unrestricted slit drain at the low end.
- Sand: Chemically inert, coarse horticultural/builders sand with sharp angular grains (like granulated sugar). Zero silt/clay. No limestone, coral, or beach sand.
- Fish: Nile tilapia (Oreochromis niloticus), preferably all-male. Stock 80–100 fingerlings (~10–15 g) per 1,000 L.
- Plants: iAVs excels with fruiting crops – tomatoes, cucumbers, peppers, melons, eggplant, squash. Maintain roughly 50% fruiting crops and 50% leafy greens/legumes.
- Power: For pumps and aeration. Can be grid, solar with battery, or generator. Backup power/equipment is essential infrastructure.
Other: Water pump, timer, air pump with air stones, fish feed (avoid fortified commercial feeds with excess Zn/Cu/S), water test kit, and a food-safe liner if not using sealed containers.
Choosing Your Technology Level
iAVs exists on a spectrum: from a Low‑Tech iAVs (a timer, a pump, and natural sunlight) to a High‑Tech setup with increased monitoring, sensors, and automation. The choice is entirely the operator’s. Both ends of the spectrum rely on the same sand biofilter, the same feed‑input logic, and the same biological equilibrium. For a deeper dive into the options, see the separate article on iAVs technology levels.
Skills and Knowledge
Operating an iAVs requires a blend of horticultural attention and procedural discipline, yet the demonstrable success of a novice operator in the USDA‑funded Boone Mora trial shows that no prior specialised farming experience is mandatory – provided the operator follows the established design and management protocols.
Basic gardening or plant-growing experience is highly valuable because that is most of the work. Any familiarity with keeping fish is helpful for the smaller aquaculture component. You do not need hydroponics or aquaponics experience – iAVs operates on fundamentally different principles.
What you’ll develop: The key learning tool after system establishment is keeping records of actions and observations Effective husbandry consists of informed, proactive management decisions. Over time, operators develop an intuitive understanding of the system through regular observation.
iAVs is 90% Horticulture / 10% Aquaculture
The 10% aquaculture — fish management is straightforward because the iAVs design simplifies it to following the standard recommendations given. No water changes, no solids removal, no biofilter maintenance. The sand, microbes and plants handle all of that.
The 90% horticulture – this is where nearly all your daily attention and decision-making goes. Plants are the living filter. If you neglect the horticulture, the water quality fails and the fish may die. The fish are relatively low-maintenance if you stay on top of the plants.
In conventional aquaponics, plant roots are mainly surrounded by water. Most of the biological filtration happens on wet surfaces where microorganisms form a thin layer called a biofilm. Because of this, aquaponics is best understood using the science of biofilms and wastewater treatment microbiology.
iAVs is different. The plant roots grow in sand containing water, air, minerals, organic matter and microorganisms. This creates a true rhizosphere — the biologically active zone immediately around plant roots where roots, microbes, organic matter, minerals, water and oxygen interact.
That means the main ecology supporting iAVs is much closer to soil ecology than wastewater filtration.
Put simply: aquaponics depends mainly on microbial life attached to surfaces in water; iAVs depends mainly on the complex root-zone ecology that develops inside an aerated mineral growing medium.
- “Water returning from the biofilters to the fish tanks had approximately half the total ammoniacal nitrogen and nitrite-nitrogen concentrations of the irrigation water drawn from the bottom of the fish tanks.” McMurtry, M.R., D.C. Sanders, J.D. Cure, and R.G. Hodson. 1997. “Effects of Biofilter/Culture Tank Volume Ratios on Productivity of a Recirculating Fish/Vegetable Co-Culture System.” Journal of Applied Aquaculture, 7(4): 33–51. ↩︎
- “The study showed that pH in the recirculating water could stabilise in the range of 6.3 to 6.5 without any lime addition, when plants were actively growing in the biofilters.” McMurtry, M.R., D.C. Sanders, J.D. Cure, and R.G. Hodson. 1997. “Effects of Biofilter/Culture Tank Volume Ratios on Productivity of a Recirculating Fish/Vegetable Co-Culture System.” Journal of Applied Aquaculture, 7(4): 33–51. ↩︎