Hey guys! Glad to see there's still some interest in these plants!
It really is NOT easy to grow them in small artificial containers. I've had a miserable time of trying to do that myself over the last 25+ years! They really are part of a complex symbiotic community, and without the proper balance involving all of the constituent members, (companion plants, small snails, shrimp and other crustaceans, copepods, Daphna, even small worms like tubiflex, and insect larvae), it's doomed to fail. When these things ARE in place, they grow faster than any terrestrial CP, and even faster than most Utrics! They will grow from 1.2 to 3 axils per day, and double or triple their growth points every few days, often doubling their entire population every week or less! But this is based upon how much it eats, it has a direct response to the presence of unlimited food by a burst of growth, and in response to an unlimited source of food, it will undergo unlimited, and unbounded exponential growth. The plant has no roots, so that the ONLY way it has to take in those nutrients is by its traps, and how much they eat!
However, there are several other factors involved: the plant requires large amounts of CO2 for photsynthesis, and often releases the excess nitrogenous matter that it cannot use for its own immediate needs, and this is provided by the close proximity of large monocot plants that are heavy nitrogen feeders, and release large amounts of CO2 from their roots by respiration in responce to the increase in nurishment, so that it is a fully reciprocol (mutualism) symbiotic relationship.
Then there's the issue of cleaning out the spent carcasses in the older traps; this is provided by the presence of small snails and copepods which also graze on any filamentous algae that attempt to attach onto the Aldrovanda. The Aldrovanda actually serves an an effective predator in order to keep the population of the zooplankon from undergoing catastrophic cycles of population explosions and crashes, yet another amazing symbiotic relationship.
Again, these nitrogenous compounds must me removed quickly by the roots of their companion plants, otherwise, algae will sieze the oppertunity and quickly overwhelm everything. The zooplankton community are generally algae feeders as well, so that is part of this balance. It's NOT the chemistry of the water, but this community of symbiotic creatures that makes all the difference. Some areas of the ponds have a very conspicuous presence of clay, and the water tests neutral (pH=7.0) to slightly alkaline! In these clay pits, they are often found growing in very shallow puddles, no deeper than a few inches, if that, directly above a large mat of tubiflex worms dancing directly under them!
Water depth is always very shallow, never any deeper than just a few inches, "ankle deep" anything more than "knee deep" is too much for them; but this is where the population density of the zooplankon community is the highest and most concentrated and where they are the closest to the roots of their companion monocot plants.
If you try to grow them in some large container, I would suggest that you set one up with some clay, tubiflex worms, and several large grass-like plants such as cattails (Typha sp), Papyra, or other Juncus sp., or similar plants so that it looks like you're growing these plants first, but upon closer inspection, one might happen to notice that there are also some Aldrovanda strands that just happens to be growing around the bases of those plants as well.
I hope this helps! In a few months, my ponds will thaw out and I will have access to millions of them again!
