The conversion from ppm to gpg: ppm=17.1 x gpg, or gpg = ppm/17.1 You have ~30 gpg hardness. You need at least 1.5 cu ft. To be on the safe side, I would go with 2.0 cu ft, particularly if you would like to set up the softener for good salt efficiency.

The following requirements are for an industry standard softener. If you are looking for a non-electronic softener, Kinetico offers the more reliable options at a premium price (and you would need to deal with a local Kinetico rep). Any decent softener vendor should be able to provide the following:

1. High quality American or German made resin. This will provide a tight size distribution for optimal flow within the resin, longer resin life, and more reliable, predicable water softening.

2. Since you have CITY WATER: 10% crosslinked resin. The oxidizers that city water treatment plants use, such as chlorine or chloramine, are harmful to softener resins. Higher crosslinking will resist chemical attack longer.

3. Top basket. This serves two purposes. It sets up a proper water distribution during normal operation and prevents resin loss during backwash.

4. Gravel underbed. The gravel underbed is there to set up proper flow patterns, improve backwash, keep the bottom basket in place, prevent basket failure, and prevent channeling. Many softener sales companies like to leave this out or sell softeners with a vortex system instead. Vortex systems weigh less than gravel so they cost less to ship. In addition, they are a more expensive item that adds profit for the softener salesperson, but provides no additional benefit to the homeowner . It simply adds another piece of equipment that can break.

5. Fleck or Clack valves. These set the industry standard. Be aware that you will not be able to purchase Clack valves online. This is not a problem if you purchase locally.

6. The valve should regen based on water usage, not time.

7. Install the softener with a three-valve bypass. This will make it much easier if you ever need to remove the softener for repairs or wish to take it with you when you move. Use full-port, quarter-turn valves.

8. Noryl bypass. Most softeners are available with either Noryl or stainless bypass valves. Both are good valves, but the noryl tends to be more reliable when not used for long periods of time. This is a redundancy if you install with a proper three-valve bypass. I prefer a bit of redundancy but it is your call.

9. Brine tank: Although either round or square will work, round brine tanks are more structurally sound and will not deform like a square tank will. Additionally, since you need a softener 1.5 cuft or larger, a square tank will most likely be too small.

10. If you live in a cold climate, ensure equipment is stored in a climate-controlled environment. Frozen softener resin is damaged softener resin.

11. Purchase a Hach 5-B test kit. You will want to periodically check to ensure your softener is working correctly and this kit is your best option.

aliceinwonderland_id Do you have any suggestion of where to purchase a unit? We are looking at the fleck 5600sxt and 64,000 grain round tank, DIY install.

The Genesis lower salt claim is misleading - Any programmable softener can be set to a specific salt dosage for regeneration. The only advantage to counter-current (in this case "upflow) regeneration is that the resin at the outlet end of the softener will be the most regenerated portion, meaning that hardness bleed will be slightly lower. However, we're talking about a 1-2 ppm difference in hardness bleed (remember 17.1 ppm to get one grain) so it is highly unlikely you would notice the difference.

Further, the calculations presented on their website are just plain wrong. They neglect entirely the capacity drop due to lower salt dosage, which means that their example of a family of four, would end up with hard water for fully half the time. Just my personal opinion here, but they are either not competent to make softener calculations, or they are lying - neither would make me comfortable believing anything they have to say about their product.

In your specific situation, with 30 gpg hardness, using a salt dosage of 3 lb salt / cu ft resin (the dose Genesis recommends) would not provide good softener performance.