Some guidelines for fertilizing CPs, Drosera in particular.
Hanrahan, Bob (1986) Simplistic CP Fertilization Facts. Carniv. Pl. Newslett. 15(2):53 (PDF)
Try a lower concentration. You may be having photo-toxicity issues too. Try fertilizing very early in the morning or early evening. If they are outdoors or in a greenhouse there is plenty of micro fauna (springtails etc.) but additional fertilization about twice a month does not hurt. I would not fertilize more than twice a month until you see how the plants react over a few months.