Types of Aquaponic Medians

Aquaponics is a technique where hydroponic plants receive hydration and nutrition from fish tank water, which in turn provides clean water for fish. Aquaponics is efficient as it allows farmers to cultivate two products in a highly sustainable manner. Knowing the advantages and disadvantages of different types of aquaponic media enables you to make good decisions with regard to designing an aquaponic farm.

  1. Characteristics

    • Hydroponics, in simple terms, is soil-free plant cultivation. Aquaponics distinguishes itself from hydroponics by integrating aquaculture as additional support for a hydroponics setup. In an aquaponics setup, water from aquaculture is used to nourish the plants, and the plants in a hydroponic setup act as a filter and purifier for water used in cultivating fish. There is no difference between aquaponic and hydroponic media. The ideal aquaponic medium should be pH neutral, provide adequate plant support, good moisture retention, and good spacing for air exchange. Ideal aquaponic media comes from both mineral and plant sources.

    Clay Pellets

    • Hydrocorn or man-made clay pellets are the best for aquaponic designs that make use of a continuous drip system. This medium provide enough drainage, air space, and plant anchorage. They are also easy to clean and can be used indefinitely. However, hydrocorn has almost zero water retention.

    Perlite

    • Perlite is a porous kind of volcanic glass which has good wicking action and is ideal for wick-type systems. It is also a relatively inexpensive medium. Perlite, however, does not hold water well and the dust from perlite is bad for the handler's health. Handlers should use a dust mask when handling this material.

    Vermiculite

    • Vermiculite is similar to mica rock and has good moisture retention. Its moisture retention qualities make it good to use with perlite, usually in a 50/50 ratio. It is also an inexpensive medium well suited for ebb and flow systems. Its moisture retention property is also its drawback and therefore is usually balanced with perlite.

    Rockwool

    • Rockwool has rather balanced properties, having good moisture retention, good aeration, and is ideal for individuals without monitoring equipment. A major drawback for using this medium is that it tends to accumulate salts and has to be flushed with pH-neutral water. The rather tedious nature of cleaning up rockwool makes it discouraging for reuse by most hydroponics practitioners.

    Coconut Fiber

    • Coconut fiber is the only known completely "organic" medium. It has good moisture retention that's superior to rockwool, making very good for systems with intermittent watering cycles. It also has root stimulating hormones and provides some degree of protection against root diseases. Its biodegradable properties also make its disposal environmentally friendly. Some farmers may find coconut fiber to hold too much water and so mixing it with 50 percent expanded clay pellets provides a good balance.

    Selecting the Best

    • The right aquaponic media varies from one practitioner to another. It depends on numerous circumstances such as aquaponic facility design, availability and price of materials, and experience. The best aquaponic medium usually involves a mix of different kinds of materials to get an ideal balance.