Nitrogen Cycle – A naturally occurring cycle that turns Ammonia, from fish waste and aerobic decomposition, into Nitrite, and then Nitrate, progressively less harmful forms of Nitrogen.  This process is the primary source of nutrients for the plants in an aquaponic system.

Aquaponics – A combination of Hydroponics (growing plants in nutrient rich water) with Aquaculture (raising fish in closed loop systems).  Uses 1/10th the water of traditional soil agriculture.  A sustainable option for growing a carbohydrate and protein source in a small area. 


Chemical Filter – A media or chemical designed to filter out specific elements.  Most commonly used chemical filter is carbon.  Other products are available for Phosphate, Ammonia, Nitrate, etc…


Mechanical Filter – An inert media like a sponge, net, or floss that physically traps particles and detritus.  Catching and accumulating solids that need to be physically removed from the water column.  It is important to remember to frequently clean and rinse these media to avoid too much waste fouling the filter.


Biological Filter – A filter with a porous media and a high oxygen environment designed to encourage the colonization of aerobic bacteria.  These bacteria convert toxic Ammonia into Nitrate through the Nitrogen cycle.


Nutrient Removal – The actual removal of solids, compounds, or elements from the water column.  Extremely important to remember that until an element is physically removed from the water column it is still in the water.  Most effective by discarding plants or algae with bound nutrients or cleaning mechanical filters.


Nitrogen [N] – The primary nutrient for plant growth.  Responsible for leaf development and growth.  The end product of the Nitrogen cycle and the main nutrient for an aquaponic system.  Undesirable, but tolerable, in most aquariums but unwanted in reef aquariums


Ammonia [NH3] – The main waste product produced by fish and aerobic decomposition.  Toxic to ecosystems in small amounts around .05 ppm.  First stage of Nitrogen or nitrification cycle.  Converted into Nitrite by bacteria.  Water changes are most effective to reduce levels, with ammonia binding products being a temporary solution.  Most common sources of Ammonia are over feeding and over population.


Nitrite [NO2] – Toxic to ecosystems in measurable amounts.  Lethal around 10 ppm.  Secondary product of the Nitrogen or nitrification cycle.  Converted into Nitrate by bacteria.  Salt can be an effective treatment for fish exposed to Nitrite.  Water changes are most effective to reduce levels.  Look for gasping or gulping at the surface as Nitrite damages gills.


Nitrate [NO3] – Tolerable in small amounts in most aquatic systems.  Reef aquariums desire 0 ppm, most freshwater aquariums can tolerate levels to 80 or 100 ppm,  and some aquaponic systems run up to 300 ppm.  The more Nitrate in a body of water, the more soluble Nitrogen is available for plant growth.  If no plants are present, elevated levels of Nitrate will encourage undesirable algae growth.  To reduce high levels, water changes are most effective.  Some Nitrate reducing chemical filters are also available.


Dilution – Water changes are the best process for dilution in an aquarium.  It is important to understand that changing half of an entire body of water effectively removes half of the nutrients, chemicals, or compounds that may be in that water.  Only if those nutrients, chemicals, or compounds are at a zero level in the replacement water.  It is important to always use the highest quality water possible.


Photosynthesis – the process by which green plants and some other organisms use sunlight to synthesize foods from carbon dioxide and water. Photosynthesis in plants generally involves the green pigment chlorophyll and generates oxygen as a byproduct.


Respiration – a process in living organisms involving the production of energy, typically with the intake of oxygen and the release of carbon dioxide from the oxidation of complex organic substances.


Transpiration – the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released to the atmosphere. Transpiration is essentially evaporation of water from plant leaves.