Using all FF nutes on their feeding chart except wholly mackerel and kel p me kelp you. Does the EC/PPM at the top correlate or are they used individually? In other words should I use EC if checking with a TDS or PPM? If I add nutes to get to say, 1.8-2.1, should my PPM be at 1260-1470 or are they not calibrated together? If I adjust to the recommended EC, my PPM is quite a bit different.