as the guy above says you have to have your fundamentals such as your good quality high powered fan( i run mine all the time the light is on), good fresh air (or co2), good light reflection ect.

Also very important in my opinion when growing hyroponicaly is that you can be much more acurate investing the extra cash in a proper high acuracy PH meter and trunchon nutreint meter because especially in hard water areas you have to be very accurate in caculating the compensations of all the dead unusable salts in the water.

Super thrive and gardian angel are also very good investments for ensuring maximum stress managment for your crops!! hope that helps a bit mate?? happy growing.