A and B fertilisers for coco fibre, growth and flowering

The same fertiliser feeds very different crops. If you are growing a tomato in a 20-litre coco fibre pot, it receives the solution every day in summer, a planter of salad leaves every two or three days, and a tub of herbs on demand, as soon as the surface of the grow medium dries out. For fruiting vegetables, Green Sensation, rich in phosphorus and potassium, is added from the sixth week, while leafy vegetables make do with the base formula alone until harvest.

In an aquaponic system, nitrogen already reaches the plants in the form of nitrates, produced when the filter bacteria break down the fish waste. Cocos A and B was not formulated for this water, so it should never be poured into the pond. Its bottle A also supplies some ammoniacal nitrogen, whereas the total ammonium in a system must stay below 1 mg/L for the health of the fish. Deficiencies in an aquaponic system mostly concern iron, potassium and calcium, and they are corrected with a DTPA chelated iron and potassium or calcium bases.

The fertiliser has its place right alongside. Tomatoes in coco fibre pots in the greenhouse, a shelf of seedlings destined for the vegetable garden or bags of coco fibre on drip irrigation can be fed without risk to the fish, provided their drainage water does not return to the pond. The water removed during a partial water change in the pond can in fact be used to water these pots: it already contains nitrates, and you add Cocos A and B at a reduced dose, adjusted with a conductivity meter. The article which fertiliser to use in aquaponics reviews what can go into the system itself.

At 4 ml of each part per litre, the 2 x 1 litre kit makes up 250 litres of solution, enough to feed a few pots of coco coir on a balcony or in a greenhouse for several weeks. The 2 x 5 litre kit makes up 1,250 litres, for a drip irrigation system or a whole greenhouse grown on coco coir for the entire season. These volumes correspond to the maximum dose; at the doses in the feeding schedule, which are lower early in the crop, each kit lasts longer. Close the bottles after use and store them away from frost and heat, out of the reach of children.

The 100% COCO growing schedule starts with 15 ml of Cocos A and 15 ml of Cocos B per 10 litres in the first week, then adds 5 ml of each part per week up to 35 ml in the fifth week, a dose that is maintained until the tenth. The target conductivity goes from 1.3 to 2.5 mS/cm with manual watering, tap water included, and from 1.5 to 2.5 mS/cm with drip irrigation. It never exceeds 3.0. For a lettuce or a basil plant that stays in leaf, you repeat the second-week dose, 20 ml of each. With manual watering, the schedule combines Power Roots and Pure Zym at 10 ml per 10 litres at the start, and drip irrigation replaces Power Roots with Hydro Roots. The final week is done with clear water on crops harvested in a single go.