Are you referring to the light commercial systems? looks like 20" filters, pumps and may need pressure or atmospheric tanks, 200-500 GPD. Those look actually fairly cost effective compared to Kinetico. Either way - don't want to get swindled.
I bought a 500 GPD skid from Titan (
http://www.amazon.com/dp/B0051PRBZQ/?tag=skimlinks_replacement-20) for a bit under $2K. I thought that fairly reasonable for 500 GPD. Not that I use 500 GPD. It's only plumbed into my brewery and lab. What I was after was the 20 gph that 500 GPD implies. I can collect the 50 -75 gal RO water I need to brew in a couple of hours and if I don't collect enough I can get plenty more while I am brewing.
I put the system together myself, had too much fun doing it and spent way too much money on tanks, controls, pressure valves etc. So I guess I got swindled but it was a do it yourself con. Pic of the system at
http://www.pbase.com/agamid/image/124857348. An unanticipated benefit was that when the well failed on boxing day we had an ample supply of drinking, toilet flushing, cooking water until they came out and replaced the pump several days later.
Note that there are a million possible configurations for a larger RO system wrt pumps, whether to have an atmospheric tanks and if you do what size, pressure tank sizes, controls (float switches, pressure switches, pressure relief valves) etc. If you don't put it together yourself then you are relying on what someone else tells you you should have.
Of course, the sites seems to imply that I should scale to twice the capacity to reduce pump wear.
That's clever!
It also looks like I should get a much more extensive water test if I do this whole home. Are there really any benefits to this? or am I worrying too much.
Yes, there is a reason for a more extensive test in larger systems because they are adjustable for recovery and the maximum allowable recovery is that which keeps the all the salts in the concentrate below their saturation levels. I put your numbers into my spreadsheet and was very surprised to see that your 'limiting salt' is calcium carbonate. Even though your water has been softened it is still super saturated with respect to calcium carbonate. The saturation pH is 8.25 and your reported pH is 8.3. The calculation tells me that your maximum allowable recovery is 0%. Your source water will, theoretically, deposit chalk on and foul your membranes.
The solution to this for you would be to inject acid to lower the pH. At pH 7.5 calcium carbonate would still be your limiting salt and you could operate at 44% recovery (approximate number). But if you have high silica content that can be limiting. For example the 28 mg/L in my well limits me to 47%.
A small system will meet my brewing and drinking water needs it seems.
Solving the pH problem in a whole house system would doubtless be expensive and require elaborate equipment. Beyond that anyone who has dealt with a widowed mother or other relative knows that all this fancy automatic stuff can be a problem if you are not there to operate/fix/maintain it.
You will still probably have to do something about the pH/huge alkalinity with a small RO system or even the ones that run less than 20% recovery won't last long. Of course if they are cheap enough you can throw them away (or their membranes anyway).
You have over a gram of junk in each liter of your water. Little wonder that you see encrustations on plumbing fixtures. A whole house system has its appeal for water this bad but it has its downside too.
I was told that the extra waste going into the grey tank in my aerobic septic could be problematic. However the system was sized to support a large family, and there are just 2 of us on it.
With 50% recovery and assuming that most of the recovered water winds up as grey water (i.e. most of it is used for washing as opposed to drinking/brewing) that will double your water consumption and grey water load i.e. as if there are 4 people. If the system is sized for 4 then things should be OK. The alternative is to dump the concentrate elsewhere but as it will contain 2 g/L stuff (mostly sodium bicarbonate) I would be reluctant to dump it on the lawn for example.
The effluent is also treated with Chlorine before being sprayed.
???
And a lot of waste water is bad when we are in an extreme drought down here.
That drives you to set up for higher recovery and that means removing the bicarbonate with acid before RO. This would have the added benefit of less bicarbonate in the concentrate but the potential costs have been noted.