I keep my carnivorous plants in some spare space in a propagation greenhouse at the University I attend. The plants are all watered (by the greenhouse manager) through a fertigation system which delivers water soluble fertilizer through the irrigation system. My plants are on one of the "Do Not Fertilize" benches, so when they are watered, the fertilizer delivery system is turned off and the irrigation line is flushed. My plants never get fertilized, per say, but they are probably getting some trace amounts when they are watered, since the same irrigation line is used. I only grow Nepenthes right now, and I seriously doubt such small trace amounts of fertilizer would harm them. If anything it is helping them. I have ideal conditions for subtropical sundews and Mexican butterworts, so I have been thinking of adding them to my collection. Would they be more sensitive to extremely small trace amounts of fertilizer than Nepenthes?