Thanks for the tips on interpreting the water report. Here's my take on what I'm reading at the PDF linked below. pH: avg 8.11, max 8.64 - From the tap, my aquarium test kit tells me I get water closer to the high end of the reported pH range: 8.4. I understand this to mean that I should add vinegar to the water when I water the plants, to bring the pH closer to 6 or 7. I will mix up some samples at various concentrations and use the test kit to determine how much vinegar to use. Alkalinity (Total as CaCO3): avg 94 ppm, max 107 ppm - Based on Oxboy555's recommendation above, with alkalinity around 100 ppm I plan to flush the pots regularly using Al (Tapla)'s techniques, to wash salts out of the 5-1-1 potting mix I will use. Using the indices described on the Wikipedia page for Hard water, I can determine: Ryznar Aggressive Index: avg 7.58, max 8.29 -- "For 6.5 For RSI > 8 water is under saturated and, therefore, would tend to dissolve any existing solid CaCO3 For RSI Langlier Index: avg 0.27, max 0.76 -- "In practice, water with an LSI between -0.5 and +0.5 will not display enhanced mineral dissolving or scale forming properties. Water with an LSI below -0.5 tends to exhibit noticeably increased dissolving abilities while water with an LSI above +0.5 tends to exhibit noticeably increased scale forming properties." Calcium Hardness: avg 104 ppm, max 125 ppm -- Moderately hard to Hard water Calcium: avg 41.7 ppm, max 50 ppm Magnesium: avg 16.6 ppm, max 19.6 ppm Potassium: avg 3.86 ppm, max 4.26 ppm Sulphur: not listed -- This is where I'm lacking any useful context. Is 41 ppm a lot? A little? What target should I be comparing these numbers to? I would appreciate some input from our brilliant experienced growers, soil scientists, and chemists in the group. Thanks! Here is a link that might be useful: Physical, Mineral, and Metal Characteristics

What they said. All I have to add is for my money (and FISH!) I would/do always add dechlor to the water in a separate bucket, dechlor first then water so they well mix, then add that to my pond. Safe & sure all gets treated. The other method I've heard of takes advantage of the fact that the dechlor is itself harmless to fish, so it is safe to treat your whole pond with it then just drop your hose in. (Don't let the hose run overnight! It's happened!) I get Beckett conditioner at the home store (the blue one) and a $10 16 oz bottle will treat 1920 gallons of water. Another approach is to get an inline carbon water filter to strip out the nasties and again just drop the home in. In this case, as long as you don't run out the filter you can leave the hose run a week or two. And the last method that I know of, don't like, but is told by Doc Johnson on the koivet sight is to get a drip irrigation head and slowly, constantly add city water directly to your pond, letting it overflow. At these very low flow rates the toxic elements never get to stressful conditions, and you get a constant water exchange for very little work.

There are lots of posts about tankless electric. The biggest issue is the amount of current they draw for a whole house setup. There is virtually no savings of energy for a tankless electric over a tank electric (about 2-3%) but the electrical service requirements for a whole house electric tankless are significant and expensive. There are point of use applications that make sense for electric tankless, but not generally whole house. Consider solar domestic hot water with electric tank heater as backup(could be less expensive than the desuperheater) or simply an electric tank heater.

The 2-main facts you stated are that you are doing a geothermal liquid-to-air system with a desuperheater to preheat the domestic hot water (DHW). The second fact you stated is that a regular active, as in electrically powered, 50gal domestic hot water tank would meet all your hot water needs. Based on these 2-facts, all that required is a passive buffer tank that is properly plumbed between the geothermal heat pump’s desuperheater and another active 50gal electric domestic hot water tank. That’s it! The reason for the buffer tank is that the desuperheater wants to see a greater temperature differential between itself and the entering water, as will be provided by the buffer tank, without the buffer tank you will have hot water circulating from the active tank through the desuperheater with very little temperature differential. That would be very inefficient. During the summer when you’re air-conditioning anyway your domestic hot water will be essentially free as the heat removed from your home will be transferred to the buffer tank rather than just exhausted to the outdoors as with an air source heat pump. The electric elements in the active tank will either hardly come on or not come on at all, depending on the amount of air conditioning required and domestic hot water consumed. Have a look at the link below for informational reference regarding high quality buffer tanks. Remember that the buffer tank should have no electric elements or electrical connections at all. Your geothermal contractor that has experience doing this should plumb it. A plumber that lacks this experience might get it wrong! Verify the credentials and references of your geothermal installer. Read some of the other numerous geothermal posts I’ve written on this site. I hope this helps. SR Marathon Buffer Tank, see model # MTS50200 (no electric elements)