Using The Alkalinity Calculator
Step-by-step instructions for using the updated alkalinity calculator online.
April 15, 2010
If you have tried to use the Greenhouse Media Lab Acid Addition Calculator, the alkalinity calculator from Purdue University and North Carolina State University in the last couple years, you may be disappointed that it no longer worked. The problem lies in the fact that when Microsoft updated Excel, the alkalinity calculator was no longer compatible with the program’s latest version.
Fortunately, a solution was developed with the support of the Fred C. Gloeckner Foundation. If you’ve never used the alkalinity calculator, then welcome to the redesigned alkalinity calculator, AlkCALC.
AlkCALC is an application that easily calculates the amount of nitric, phosphoric or sulfuric acid required to neutralize alkalinity in your irrigation water to a desired level. In addition, it will determine the amount of nutrients added by acid injection and the cost of your specific acid injection needs.
Unlike previous alkalinity calculators, AlkCALC does not need to be downloaded from the Internet. It is embedded into a website: www.nhfloriculture.com. You will be directed to the University of New Hampshire Cooperative Extension Greenhouse and Floriculture homepage. On the left-hand navigation bar, click on “Grower Tools” (Figure 1). This will take you to the GroCALC page that gives you the choice of three different calculators (AlkCALC, FertCALC, and PGRCALC). Clicking on the AlkCALC logo will start AlkCALC (Figure 2).
AlkCALC is easy to use. Upon opening the program, you will need to input less than 10 items of information (Figure 3). Enter your company’s name and your name, and these will be carried though to the results. The next information AlkCALC needs is the pH and alkalinity of your water. You will need to do your own pH and alkalinity tests, or send a water sample to a testing lab. Notice there is a drop-down menu to the right of the input box for alkalinity. This menu will allow you to choose the appropriate unit of measure that your alkalinity test was conducted in: meq/L, ppm HCO3, or ppm CaCO3.
Next, input the desired level of alkalinity or desired pH of your irrigation water after acid addition. Again, there is a drop-down menu to select the unit of choice. Finally, the last selection you need to make is the type of acid you wish to use. AlkCALC can use one of eight commonly used acids: phosphoric (75 or 85 percent), nitric (61.4 or 67 percent) and sulfuric (35, 50, 66 and 96 percent). Choose your acid, or if you want to make a comparison, choose “all acid types”). Now that all the appropriate information has been provided, click on “submit” to have AlkCALC make your calculations.
The next screen you see will display the information you input on the previous screen, as well as the calculated alkalinity and pH values of the water after the addition of the recommended acid amount. The most important information, the amounts of acid to mix with your irrigation water, is found mid-page. To obtain a print copy, click on the “print report” button at the bottom of the page and the results will be displayed in a printer-friendly format.
If you wish to store your results electronically, AlkCALC will create a PDF of the results if you click on “print PDF.” You will then be prompted to open the file in a PDF viewer in which you can save the file, or save it directly to a user-specified folder on your computer.
AlkCALC will also estimate the cost of acid addition in your situation. By selecting the “cost comparison” tab at the top of the output screen, you can input your cost for each acid and AlkCALC will calculate the cost of treating 1,000 gallons or liters of water.
Brian A. Krug (firstname.lastname@example.org) is assistant professor at the University of New Hampshire Cooperative Extension. Brian Whipker (email@example.com), who provided the updated version of AlkCALC, is a professor in the Department of Horticultural Science at North Carolina State University. The authors thank Mike Toepfer for his work in the conversion of calculators to Web-based applications. The update of AlkCALC was made possible by support from the Fred C. Gloeckner Foundation.