This is an awesome build so far! You have some cojones testing that for leaks in the house, yikes.
If you feel bad about the waste water when making RODI you could get a permeate pump, got mine here...
http://www.thewaterguy.ca/catalog/vi...te-pump-73.htm
I make about 70 gallons of RO to 30 gallons of waste. Then the waste gets used to either flush the toilet or water the plants in the summer, this time of year though I don't bother collecting the waste
Keep us updated on the detailed progress, looking good