why are you dosing Ca? Eco should give you plenty. Good Ca is 20 - 30 ppm.
Your Mg of 20 ppm is too high. Should be 5 ppm. Do you dose any MgSO4?
Is CO2 30 - 40 ppm?
What kind of TE do you use?
Because your NO3 is down, need to stop dosing DS and go for 3ml SS Solution and 3ml PF Solution. This will add K and NO3.