I dont know Cape, Ive never kept track of how much change was required.. sorry mate, cant answer that...
but just FYI
....The amount of nutrients obtained from either
prey or from the soil seems to vary substantially.
Sarracenia leucophylla can get 60 times more ions
from the prey than from the soil (Gibson,
1983b). Nepenthes mirabilis gets about 60% of its
N from insect prey, whereas in Cephalotus it is
only 30% (Schulze et al., 1997). In Drosera
rotundifolia about 50% of the total N is of animal
origin (Millett et al., 2003), and in D. hilaris
68% (Anderson and Midgley, 2003). The protocarnivorous
Roridula gorgonias, which needs
symbiotic hemipterans for digestion, even up to
70% of N comes from animals (Anderson and
Midgley, 2003)......
The roots of carnivorous plants
Wolfram Adlassnig1, Marianne Peroutka1, Hans Lambers2 & Irene K. Lichtscheidl1,3
1Institute of Ecology and Conservation Biology, University of Vienna, Althanstrasse 14, 1090 Vienna,
Austria. 2School of Plant Biology, Faculty of Natural and Agricultural Sciences, The University of
Western Australia, Crawley WA 6009, Australia. 3Corresponding author*
Received 30 April 2004. Accepted in revised form 31 August 2004