Potassium Nitrate contain two of very important macro nutrients for healthy plant grow. They are know as macro nutrients because plants uptake for those nutrients is much more then trace (micro) nutrients.
Nitrate (N) is second most important macro nutrients for plants right after Carbon.
Good level of Nitrate also prevents BGA (Blue Green algae).
Nitrate deficiency symptoms
Older leaves turning yellow. Stunned grow and / or very small leaves on new grow.
Plants requirements for healthy grow
Carbon (supplied as Carbon Dioxide CO2)
Trace elements (micro nutrients)
Store in a cool, dark place
4 tsp. Potassium Nitrate
500 ml Water
Dose 10 ml per 50 litres of aquarium water 3x a week