1. WATER IS ALWAYS DIFFERENT - GEOGRAPHICALLY, AND OVER TIME.
Think of it this way: Most technologies run on electricity, which comes to us as a stable, quantifiable power. (Electricity is the same all over America. )
Water technologies, however, run on water - which is always variable. Water comes from different sources, and the balance of what's within is continually shifting. Therefore, there is no single system or technology that is always "the best". It depends on the water conditions in play, and what you are trying to achieve.
Of course, there are generally reliable predictions to be made. That's where our experience comes into play.
2. KNOW YOUR WATER.
If your source is a private well, it's probably a good idea to have the water analyzed so you can make an informed decision. If it's municipal water, then you probably don't have to bother with an analysis since we are likely to know its characteristics well enough already. (Check the available municipal water analyses on this site.) If it's rain water, again, we can usually predict with reasonable accuracy.
3. KNOW THE QUALITY YOU WANT TO ACHIEVE.
This depends, of course, on the use you'll make of the water. Does it just have to look sparkling clear? Does it need to be pure drinking water, i.e. equivalent to pristine bottled? Is it to be used exclusively for irrigation or gray water applications?
4. KNOW THE ESSENTIAL PARAMETERS.
What's the flow rate to be accommodated? The incoming pressure? The line size? For a drinking water system in a private home, these values can usually be predicted. But if you are custom-designing a large system, these numbers are variable and will have a lot of impact on your decisions, including cost/benefit ratios.
5. THERE ARE ALWAYS PRACTICAL TRADEOFFS - SO LOOK FOR THE SWEET SPOT.
For example, as a rule, all other things being equal, the higher quality the water you want to obtain the more space you'll need. Of course, it's not quite that simple; there are other factors to be considered. Which we tell you about on this site.