I’ve become quite spoiled and dependent on computer technology, to tell the truth. And I spend a fair amount of money every year keeping hardware and numerous programs up-to-date. So I want to share some of my experience with several technical software programs that are very helpful to those of us working with water and wastewater.

I have a number of excellent software programs that perform modeling of one type or another. GPS-X is a top-of-the-line wastewater modeling program that allows you to design and simulate just about any type of wastewater system. It’s nearly infinitely adjustable and I provide a very detailed example of how this program can be used to model a wastewater plant that I’ve done a lot of work at.

@Risk is an Excel add-in that facilitates simulation and risk analysis. Again, I provide a detailed example of how I used this software to evaluate oxygen consumption in a biological reactor comparing a point estimate to several probability distributions so you can better predict the true oxygen consumption.

Two very-easy-to-use hydraulics programs, Pipe Flow Wizard and Flow Advisor, are briefly described as well.

If you like GPS-X, @Risk, Pipe Flow Wizard, or Flow Advisor, and decide you will benefit from having them, you’ll have to buy the software. But there are several well-designed programs, **free programs**, that are great at modeling reverse osmosis systems. These include Avista Advisor, Dow ROSA, and GE Winflows. By clicking on each of these links you will be brought to a web page that gives an example of using each program as well as links to get to the maker of each program so you can download the software and start your own modeling effort.

Thrown into the mix of software is even **a free unit conversion program**, called Convert 123, that is well worth the no-strings-attached, quick download from the same vendor who makes Pipe Flow Wizard and Flow Advisor. You can use Convert 123 to go back and forth between many different units such as degrees F to degrees C, for example, or from gallons per minute to cubic meters per minute. And finally, there’s another simple, but very handy, free math program from Microsoft that can even do calculus called, appropriately enough, Microsoft Math.

**No matter what software you like and use, everyone should get the free Convert 123 and Microsoft Math.**