A couple of questions:

1. I am wondering how to adjust the final hardness of softened water. The reason for this is that I am installing a condensing water heater that requires that hardness be maintained between 5 and 7 gr/gal. I am starting with water that is 13 gr/gal. I have read that reducing the salt dosage allows the final hardness to be above 1 gr/gal, but it is not clear to me by how much.

2. I understand that SFR is 7gpm/cuft. (although I have seen references to it being non linear). How does one avoid channeling? Is there a minimum flow/cuft? I assume that channeling doesn't occur just because a low flow is being demanded over the short term (a single low flow tap on for 2 minutes). It must occur over a longer time if insufficient peak flow rates don't occur often enough.

3. How does softening affect TDS?

4. I have read much about salt dosage and brine efficiency, but I don't understand how to set it up. I don't see mention of salt dosage in the programming manuals for the 2510SXT, 5600SXT or 7000SXT. It is briefly mentioned in the 6700 Upflow manual. How is it set in these other controllers? Seems like I'm missing something.

5. I'm not too concerned about hardness leakage if SFR is exceeded on occasion. Why is it mentioned so much? I don't see a problem with occasional briefly elevated hardness or am I missing something (again)?

6. What is upflow brining? Is it more difficult or expensive? How much more brine efficient is it? Is it more water efficient?

7. My intention is to use one of the above Fleck valves. Any opinions about them? I am having a hard time finding a good comparison of the features and capabilities.

Thank you,