Just take it easy on that 15-30-15 fertiliser - it's extremely potent. At 5 mil per Gallon of water you're already at about 1.1-1.5 EC - and it's far too high.
Start at about half that and see how you get on - 2.0-2.5 mil per gallon and don't feed it every watering - feed it at least one plain watering inbetween.
