Symbiose turnkey aquaponics kit for garden or terrace

The two supports do not suit the same plants, which allows you to grow lettuces and fruiting vegetables side by side. On the square metre of rafts, the roots dip directly into the water, which suits fast, light crops: lettuces, mesclun, tender herbs. The 2 m² of grow medium beds hold the plants that grow tall and bear fruit, tomatoes, peppers, strawberries, because the clay pebbles give them a mechanical hold that water alone cannot provide. You therefore divide your crops according to their habit, since the lettuce on a raft and the tomato in a bed receive the same water. The pebbles also house part of the bacterial colony, which makes them a complement to the biofilter: a bed should therefore never be emptied of all its pebbles between two crops. The comparison of grow media for use in aquaponics details this difference.

In aquaponics, balance is calculated from the feed given each day, relative to the growing area. The commonly used guideline runs from 40 to 50 g of feed per square metre per day for leafy vegetables, and from 50 to 80 g for fruiting vegetables. On the Symbiose, 1 m² of rafts and 2 m² of beds therefore call for between 140 and 210 g of feed per day. A pond stocked with 25 kg of trout, fed at 1% of their body weight, receives about 250 g a day, or just over 80 g per square metre: the stock then sits at the upper limit of the fruiting-vegetable range, so at full load it first suits fruiting crops in full production. If you start in spring with 15 kg of fish fed at the same rate, the ration of 150 g corresponds more to salad crops, and the balance shifts as the stock grows. At full capacity, the unit produces up to 50 kg of fish and 50 kg of fruit and vegetables a year.

Consumption is 592 kWh per year, pumps, oxygenation and cooling included, and it runs continuously, since the bacteria in the biofilter need oxygenated water day and night. This annual average varies with the seasons, as the cooling works mainly in summer. Upkeep takes about 30 minutes a month: there is no watering, no weeding and no soil work. Your time goes on feeding, topping up the water to make up for evaporation, cleaning the mechanical filter and recording the parameters. An optional automatic feeder gives you up to 3 weeks of absence, and the FOOD+ add-on module extends that autonomy to more than a month. Make sure you have a reliable, protected power supply, as a prolonged power cut stops the circulation, the oxygenation and the cooling all at once.

Installation and commissioning are included in the price, anywhere in France, with a starter kit and support during the first few weeks. The bench is set up in a day, without foundations, and it can be assembled and dismantled without tools: you can therefore move it over the years, after emptying it, or replace a part without taking the rest apart. Its design is modular, so you start with the basic configuration and then add growing or fish-rearing capacity, including a nutrient film technique growing module. An extension is best decided after a first season, once you know what you actually harvest and how much time you have to manage.

Once the bench is in place and filled, the colony of nitrifying bacteria takes 3 to 5 weeks to establish itself in the biofilter and in the clay pebbles. The sequence shows up in your readings: first a peak in ammonium, then a peak in nitrite, then both fall back to zero while nitrate appears. Only at that point do you introduce the first trout, in small numbers, and the load begins to increase. Test the water every 2 days during this phase, then weekly; after that, keep the pH between 6.4 and 7.5, a range that is acceptable to the trout, the bacteria and the vegetables alike. Starter bacteria get the colony going faster, and the guide to starting an aquaponic system properly describes the test result that gives the go-ahead for adding fish.

A cubic metre of above-ground water in the sun warms up quickly, and temperature is the most delicate parameter to manage with trout, which prefer water below 18 °C and whose growth stops above 21 °C. The built-in cooling addresses this constraint, and you can help by positioning the bench so that it avoids the full afternoon sun. Warm water holds less dissolved oxygen just when the fish consume the most of it, so temperature should be measured just as you measure pH during the hot months. Reduce the ration if the water goes above 20 °C, since uneaten feed degrades water quality. Top-up needs also rise in summer; top up with rainwater or with mains water left to stand for 24 hours, so that the chlorine dissipates before it reaches the biofilter.