1st if you have enough money to get some distilled water from the supermarket get it, if not in a separate res. fill it up and leave it out for 24 hours. it will last you for 2 weeks in your res. that will solve your ppm problems there.

2nd the best i used was the 3 part general hydroponic nutes, floramicro 5-0-1
floragro 2-1-6, and florabloom 0-5-4.

and if you can get 1 of those kerosene pumps ( electric pump ) so that you can remove the old nutes every 2 weeks, mix your new nutes in a separate res. and fill the plants with new nutes. total time 5mins.