What is Aquaponics?

Aquaponics is the combination of hydroponics and fish farming creating a symbiotic environment where both the fish and plants thrive.   It brings together the practice of aquaculture, raising fish in tanks, with hydroponics, the practice of growing plants in a soilless environment. These sustainable indoor farms come in many sizes.  They can be small DIY farms that you can create in your house, or they can be large commercial operations.  In either case, the basic principles are the same.   First, I found a great video that will give you a great overview of Aquaponics.  It comes from the Urban Farming Guys.

Aquaponics How To: Basics

In a normal aquaculture system (raising fish in tanks), waste accumulates and has to be removed so that the fish remain healthy.   This by-product contains rich nutrients that plants filter out, and if it is pumped into a bed where the plants are growing, they will filter out the by-product.  The resulting filtered water can then be recycled and sent back into the fish tanks and the process can repeat itself.   The usual process of evaporation will slowly lower the levels of water, so at some point more water must be added meaning that the system is not completely self-sufficient, but it is pretty close.

If you are looking for aquaponics how to information about starting a farm of any size, here are some metrics you should consider:
For every 1 gallon of water in your fish tank = ½ to 1 sq. ft. of growing space for your plants

For every 1 pound of Fish to be raised you need 1 to 2 gallons of water

Building a System

The first element of the system is fish farming.   This is based on a Recirculating Aquaculture System, which is another term for a fish tank.  What is a fish tank?  We have all seen them.   They are basically an attempt at creating a pond in a tank.  This means that you have to create an environment for the fish that is sustainable and not poisonous to them.  It needs a continuous stream of oxygenated water, and a continuous removal of the waste water.   As you can imagine, Mother Nature has natural filters in her streams and ponds to remove waste created by the fish, so we have to do the same.   There is one key difference.  The density of fish population in the tank is far greater than in a stream or pond, so removing the waste is a key requirement, and pumps are critical to the entire system.  The water quality must be maintained and carefully monitored.   In addition the temperature must be kept at the ideal temperature driven by the type of fish you are raising in the tank.

Caring for the Fish

If you create the proper environment for the fish, then they should be healthy and grow quickly.   There are several other elements that you will need to pay attention to when raising the fish:
1.    Regular observation of the fish in the tank during feeding.  You should look for behavioral changes that may indicate problems.
2.    Choose the proper feed for the type of species you are raising.   It must provide a complete diet and it must float.
There are many places to find Aquaponics how to advice on the best fish to place in your tank.  In the commercial setting for Aquaponics, there are several types of fish that do well:
•    Tilapia
•    Perch
•    Trout
•    Hybrid Striped Bass
•    Catfish

By Products from Aquaculture

The bi-product in the fish effluent creates food for the plants growing in your hydroponics beds.   This is the key to making this system work.   The effluent contains a large amount of ammonia and the process of converting this ammonia is called nitrification.   This ammonia is passed through a bio filter where the oxygen in the water converts it to nitrite.  The nitrite is then transformed into nitrate.   This is all done by allowing the bacteria to colonize at the right temperature with the water at the proper PH level.   It is this nitrate rich water that becomes the food for your plants in the hydroponic grow beds.

Hydroponic System

The growing beds for your hydroponic system may be a floating medium directly on the water, or they may use a growing medium that absorbs the water but is not soil such as: perlite or ceramic stones.   By submersing the plants roots in the water, they actually feed on the nitrates removing it and clarifying it.  It is then pumped back into the fish tanks clean and ready to be recycled again through the fish.

You can find many sources of aquaponics how to information.  Here are two types of hydroponic approaches that you can use.  Deep water raft hydroponics uses Styrofoam mats with holes in them to float the plants on the recirculated water.  The roots of the plants dangle in the water and obtain all the nutrients directly from it.  The second type of aquaponics uses a growing medium, typically perlite, in which the plants are grown.  This is called Recirculating Aquaponics or Closed Loop Aquaponics.