I am considering an open loop geothermal system using water from my well.  I would like some feedback on whether there would be problems with dissolved minerals, etc, before I get too far into the planning process.  

The water test results show the following:

pH:  8.0
Calculated hardness:  54 ppm
Alkalinity 62 ppm
Calcium:  17.7 ppm
Co2: 1.39 ppm
Chloride 0.69 ppm
Conductivity:  136 uS/cmb
Fluoride:  0.07 ppm
Iron:  0.05 ppm
Magnesium 2.3 ppm
Manganese 0.14 ppm
Nitrate-nitrogen 0.12 ppm
Potassium:  4.7 ppm
Silica 29.52 ppm
Sodium:  6.2 ppm
Sulfate:  6.86 ppm
Total dissolved solids (estimated) 75 ppm
Zinc 0.04 ppm

The following were negligible:  Aluminum, Boron, Chromium, Copper, Molybdenum, Nickel, Phosphate & Phosphorus.

The only item above which exceeds the limits for drinking water is manganese, so I already know that I will have to treat for that.

Any feedback would be greatly appreciated!!

Roger

The general answer to your question is each manufacturer has a list of water quality "deal breakers". We have very hard water in my AO and tend to have trouble with plugged drains where rookies do the installation.
We do not tend to have trouble in our heat exchangers as long as the solenoids are down stream to keep the water there under pressure.
j

I took a quick look at WFs water quality table and no deal breakers jumped out, but many items they list are not on your list and there are some unit differences

WF install guides, available for public download, have the table

My overall hardness is 340 vs. your 65 so sounds like you have some GREAT water (aside from the manganese I guess).  I have had the heat exchanger get plugged a bit twice, both times because didn't keep the heat exchanger filled with water while I had it down for service or some piping modifications.  It seems to be fine as long as I keep it full of water and pressurized (as was already stated by putting the control valve downstream of the heat exchanger.

 Although it's no sure thing, because I think water pirate brought it up, if you start using a bunch of water with a geo system over time you can start pulling water from other places and water quality can change.    I read something way back about people installing a open loop systeming water in an existing well and there water quality improved dramatically.  So there's always some risk.  I tried to think of ways to make it easier to convert mine over to closed loope if I should ever have to.  I put 2 larger PVC pipes from the mech room under the floor out the back of the house to where a closed loop might go... so that someday I could put poly loop pipe  through to connect to a loop outside.  If you need a well anyway its pretty cheap way to get into geo, and if you plan ahead your not out anything if the open loop doesn't pan out (just some plumbing changes that could be minimal)... if you go open loop you just have to have possibiliyt of a closed loop install in the back of your mind I guess.