GH – General hardness (a measure of the concentration of divalent metal ions such as calcium Ca2+, and magnesium Mg2+)

KH – Carbonate hardness (a measure of the alkalinity)

pH – “power/potential of hydrogen” (A measure of the concentration of Hydrogen atoms, H+)

Alkalinity – The capacity of water for neutralizing an acid

Acid – The negative logarithm of the concentration of hydronium ions – substance that increases the concentration of hydronium ions (H3O+) in solution

Base – The positive logarithm of the concentration of hydronium ions –


that can accept hydrogen ions or more generally, donate a pair of valence electrons. A soluble base is referred to as an alkali if it contains and releases hydroxide ions (OH−)

Ion – An atom or molecule in which the total number of electrons is not equal to the total number of protons

Anions – Negatively charged ions

Cations – Positively charged ions

Chelate – The way ions and molecules bind metal ions to allow the metals to be available to plants as nutrients

Ligand – That which binds to a central metal atom

Divalent – Forming two bonds with other ions or molecules

Anhydrous – Contains no water

AOB – ammonia-oxidizing bacteria

C:N – carbon and nitrogen ratio

CaO – calcium oxide

CaOH2 – Calcium hydroxide (also called slaked lime, hydrated lime, pickling lime, builders lime)

CaCO3 – Calcium carbonate (Chalk, agricultural lime)

CO2 – carbon dioxide

CO3 2– carbonate

C – Carbon

Ca – Calcium

Cl – Chlorine

Cu – Copper

CP – crude protein

DE – digestible energy

DNA – deoxyribonucleic acid

DO – dissolved oxygen

DWC – deep water culture

EAA – essential amino acids

EC – electrical conductivity

EFA – essential fatty acids

Fe – Iron

FCR – feed conversion ratio

GAP – good agricultural practice

H+ – hydrogen ion

H2CO3 – carbonic acid (formed by CO2 and H2O as in club soda, soda water, sparkling water, or seltzer water and acid oceans due to burning fossil fuels)

H2S – hydrogen sulphide

H2SO4 – sulphuric acid (Used in acidic drain cleaner, and electrolyte in lead-acid batteries)

H3PO4 – phosphoric acid

HCl – Hydrogen Chloride (forms Hydrochloric acid the aqueous solution of hydrogen chloride)

HCO3 – bicarbonate

HNO3 – nitric acid

K – Potassium

K2CO3 – Potassium carbonate. (primary component of potash)

K2SO4 – Potassium sulfate

KCl – Potassium chloride (available as water softener)

KHCO3 – Potassium bicarbonate (an ingredient of baking powder, also used in fire extinguishers)

KOH – potassium hydroxide

LDPE – low-density polyethylene

LECA – light expanded clay aggregate

Mg – Magnesium

Mn – Manganese

NaCl – sodium chloride

N – nitrogen

Ni – nickel

N2 -molecular nitrogen

NFE – nitrogen-free extract

NaHCO3 – Sodium bicarbonate (Baking soda)

NH3 – ammonia

NH4 + – ammonium

NHO3 – nitric acid

NO2 – – nitrite

NO 3 – nitrate

NOB – nitrite-oxidizing bacteria

OH – Hydroxide (functions as a base)

μS/cm – microSiemens per centimetre

ppm – parts per million

ppt – parts per thousand

PVC – polyvinyl chloride

SSA – specific surface area

TAN – total ammonia nitrogen

TDS – total dissolved solids

UV – ultraviolet