This calculator provides the recommendations for the amount of acid to add to irrigation water in order to modify the pH and alkalinity levels. In addition, the calculator provides the amount of added phosphorus, nitrogen, and sulfur that the corresponding acids will provide, plus an economic comparison of each acid.

This tool converts the fertilizer label between units of nitrogen-phosphate-potash (N-P₂O₅-K₂O) and elemental nitrogen-phosphorus-potassium (NPK).

This tool calculates the light intensity and photoperiod required to achieve a certain daily light integral, for an electric light source such as indoor LED (light-emitting diode) lighting. 

This web tool is intended for use only as a guide, and is intended for growers managing a constant electric light source either in a greenhouse (as a supplement for sunlight) or indoors under sole-source electric lighting without sunlight.

FERTCALC is an on-line spreadsheet capable of calculating fertilizer formulations for water soluble fertilizer. It calculates values for up to four injectors, but can only calculate one fertilizer per stock tank.

When two or more different fertilizers are being mixed into one stock tank (ex. potassium nitrate with calcium nitrate), enter each fertilizer individually using the multiple stock tank options.

This tool calculates the concentration of active ingredient in a solution, for example, a liquid fertilizer or plant growth regulator.

This tool determines how many lighting fixtures you need for supplemental lighting in your greenhouse with this calculator. 

To use the lighting fixtures calculator you will need to download the linked file and open it in Excel.

This tool estimates supplemental lighting costs in your greenhouse with this calculator.

This calculator converts between different lighting units and lamp types, using data from the Plant Growth Chamber Handbook, 1997. 

This tool is designed to help growers select a fertilizer that will result in a stable pH in their substrate (growing media) over time. 

This tool calculates how much liquid or solid fertilizer or agrichemical to add into a solution to achieve a target concentration in ppm (which is the same as parts per million, or milligrams per liter).

The production week number is widely used for scheduling horticultural crops, rather than calendar date.

This tool calculates the volume and cost of soil required to fill greenhouse and nursery containers.

This tool provides computations of saturation vapor pressure, vapor pressure, vapor pressure deficit of ai and humidity deficit of air under 101.3 kPa atmospheric pressure. 

This tool summarizes published research that tests control of plant pathogens and algae using water treatment technologies.

This web tool is intended for use only as a crop management guide for water sources used in nursery and greenhouse irrigation.