The first few gallons of water should have been disgarded. When ever you change your DI, let a few gallons go down the drain also. This could have been your problem.
FWIW, I get 0-1 PPM from my RO/DI. I change the filter when it gets above 4.
BTW, if you can become a paid sponsor and work out group buys and such then you would be doing the right thing, that is the way to go about getting a good start.