New Technologies That Save Water Should Be Taken with a Grain of Salt
Many water saving products work well, and yet . . .
Enpress, the tank manufacturer, makes the following advertising claim for its popular “Vortech” brand mineral tanks for backwashing filters and water softeners:
It’s proven – we have saved over 14 billion gallons of water and counting with our Vortech® and Mid-Vortech® distributor plate technologies since they were introduced 10 years ago!
The manufacturer is, of course, basing its “proof” on the assumption that everyone who uses the tank is taking advantage of the superior backwash flow performance of the tank as compared with conventional mineral tanks with gravel underbedding. While the manufacturer’s tests show that backwashing filters built in Vortech tanks can be backwashed with up to 30% less water, it’s safe to say that only a relatively small percentage of products using Vortech tanks are actually using 30% less water as compared with similar products that use standard mineral tanks.
The reason is that Vortech tanks don’t have magic properties that makes them automatically save 30% of the backwash water. To save water, they have to be set up by the installer to have either a shorter backwash/rinse cycle or to have a more restrictive backwash flow control device installed so that fewer gallons go out the drain line. We (at Pure Water Products) use Vortech tanks on all our filters, but we take a more conservative 20% reduction in regeneration water. (Or first concern is to make sure the filter works properly. We we want to be sure it doesn’t fail because it’s starved for water.) If everyone used Vortech tanks with our setup, therefore, Enpress would have to say that they have saved 9 billion rather than 14 billion gallons.
When I asked one of our large suppliers for their setup formula for Vortech units, I was told that they set use the same setup for Vortech as for standard tank units. Although they advertise Vortech tanks as water savers, the Vortech units they make use exactly the same amount of water as their standard units. My guess is that this is the rule rather than the exception.
High Efficiency Softener Resin
The same is true for the extra efficient softener resins. Resin that can be regenerated with 4 pounds of salt per cubic foot of resin only saves salt if the installer sets it up that way. Resin itself doesn’t automatically save salt. In fact, softeners in general are among the products that are often advertised as salt and water efficient yet are set up exactly like standard models. The most sophisticated water softener does not automatically save water if it is not set up properly at installation.
Water Saving Reverse Osmosis Membranes
High efficiency RO membranes, like the new Pentair GRO units, are great water savers and they perform as advertised. But, they only save water if they are set up correctly. The membrane itself does not automatically save water: it has to be paired with a drain line flow restrictor that matches the membrane. It is the flow restrictor that actually governs how much water goes out the drain line, not the membrane. If you buy a GRO membrane from Amazon and put it on your RO unit, it will only save water if you pair it with a properly sized flow restrictor.
There is a new RO unit just on the market that boasts “3 gallons of drinking water to 1 gallon of concentrate.” We haven’t seen it or seen an explanation of how it works. We’ve had excellent performance from the Pentair GRO with its 1 to 1–one gallon of RO permeate water for one gallon to drain–ratio, but 3 to 1 seems to good to be true.
The Permeate Pump
The RO “Permeate Pump” is now a recognized water saver, and if you install it properly your revere osmosis unit will definitely fill its tank faster and shut off faster and therefore run less water to drain. The pump can be installed with or without a shutoff valve and there is disagreement about which way is better. The good thing is they save water either way, and it’s easy to tell if you have it installed right: if it makes a thumping sound, you got it right.
Advanced tanks, water saving membranes, and high efficiency resins are all significant water savers, but you should not think you’re saving water just because you own them. Most products of this type work only if you set them up right.