Keep the plants standing in a tray of rainwater or distilled water around 1-2cm deep in a bright sunny position, south facing windowsill, conservatory frost free or unheated greenhouse. I find it is best not to feed plants yourself if you are worried the plants are not catching enough insects just put them outside for a few days you will be surprised what they can catch by themselves over the summer months.
Sundews can be left to flower. Never apply fertiliser to the plants.
Around the end of October sometimes a little earlier you will notice some of the foliage starts to turn brown and black or die off, this is normal and nothing to worry about. At this time keep the plants just damp rather than wet, and cut off any of the dead foliage. All of these plants need a cold winter rest, so if you are growing your plant indoors, this is the time to move them out to a cooler position say an unheated greenhouse, porch or something similar for the winter months. The minimum winter temperature can be as low as 0oC, and around the end of February, plants will start to come back into growth, this is a good time to re-pot if necessary (our COM1 is an ideal compost), never 'over pot' there is no need, a 12cm pot will be fine for each plant. They can also be potted on October November time if they are getting a bit big for their pots. The plants can now be put back on a sunny windowsill and stood back into a tray of rainwater, March brings very quick growth, and the fly catching begins all over again...