DISCLAIMER: not fool-proof. If you are a fool, this might not work.
I didn't come up with my Aldrovanda approach. pearldiver (Paul!) did all the leg work on this. If anything I tweaked this setup to make it easier for me and less beneficial for the plants. As such, you could probably get even more growth potential from these plants with a few "reverse tweaks."
As I mentioned above, it's really more about water ecology than chemistry. A lot of folks try to inject carbon dioxide with yeast generators and what not. I have found that a balanced ecosystem keeps this "difficult" plant growing.
I obtain this balance by first building a setup before introducing the water wheels. I have always used white-five gallon buckets because they are just so darn attractive and functional (the handle, for Christ sake!), but any water-holding vessel a few gallons or more in volume will work well. A substrate of just plain peat moss does the trick for me lately. I used to mix plain clay kitty litter (no fragrance, the cheap stuff) in with the peat, too, but found it isn't necessary. I also used to put a layer of silica sand on top of the peat to help keep the muck down and the water clear, but it never worked. In fact, I have found the mucky, peaty water to be a benefit to the system. If you are using a typical five-gallon bucket aim for six or eight inches of substrate. Top it off with about a six-inch deep layer of water to start. The water level can later fluctuate from 1/2" to 7" above the substrate.
The associated plants really seal the deal for this setup. Any fully aquatic or partially submerged plant works well; anything with feathery monocot-style roots. The trick is to get the most root growth in the substrate and water to suck up excess nutrients and balance with the Aldrovanda. I have used the following: cat tails (any type, I use the large ones I pull from the local ditches), pennywort, parrot's feather, duckweed, frogsbit, water hyacinth, water lettuce, lemon bacopa (thanks, Jay!), and any of the fully aquatic Utricularia. In fact, all of the above but the hyacinth and water lettuce are in my current setup. To be successful, plant as much of the above as possible in the tank long before you introduce the Aldrovanda, like, a month or two before you introduce the Aldro. You really can't have too many "other" plants in the mix in my experience. This is to balance the system, but I'll explain why this is important in a minute.
Also before introducing the Aldrovanda, one needs to be sure that there is plenty of micro-fauna, a.k.a. fertilizer, in the water. If you setup the tank as above, and let it sit for a month or more outside, this should be no problem, especially if the associated plants were grown outside. I like to kick start my cultures with a sample of local pond water. A cup or two does the trick, and the water you collect doesn't need to visibly contain the little miscreants. They are in there, they will reproduce, and the Aldro (and any Utrics) will devour them. Some cringe at the idea of introducing possible pathogens with the pond water, but I have had no problems in that regard.
It is important to let all of this "cure" for an extended period. I have thrown Aldrovanda into new, unbalanced setups to usually successful ends, but the subsequent algeal bloom and decline that almost always happens can be a detriment to the water wheels as they try to establish themselves. By letting the associated plants and miniscule animals balance the system you can make it past this cursed algae bloom and introduce the Aldrovanda -- a rather benign water associate itself -- into a balanced little world. They are such light consumers they won't throw the setup off kilter; instead, they will indulge and grow as much as a centimeter a day and divide about once a week.
Light intensity can vary greatly, though the more sun the better for my setups. It really depends more on your associated plants' requirements, but all of those mentioned above love full zone in my experience. Aldro in full sun seems to grow much faster than shady situations for me.
As is normal, your mileage may vary, but this setup has worked well for me for three or so year now. I overwinter the buckets in my garage were it get below zero centigrade at times and the buckets ice over. Everything always bounces back by the end of May here in Zone 6b.
I have included some pictures of my main Aldrovanda bucket from today, July 12, 2015. Let me know if I can help with questions!
Richard Sivertson has the following to add. He imparted this knowledge during a conversation on Facebook. In It, he explains why ecology is so important for Aldrovanda culture.
"Aldrovanda seems to feed on mosquito larvae quite effectively and is the only aquatic CP that can feed on even the larger sizes of their stages. They also feed on a variety of other creatures from copepods to small snails to even small worms, rotifers, etc. They are very capable of growing exponentially in order to meet the same exponential growth in their prey. They are actually effective predators in controlling the zooplankton population in response to rapid population spurts, and go into decline in the lack of prey. We now have several dangerous mosquito born viruses in the New World, including West Nile, to encephalitis.
They have NO feed-back system in place to stop their carnivorous habit when they've had more than enough to eat, and have more than enough nitrogenous matter to grow and multiply, their traps never stop trapping and digesting, so they release these excess nitrogenous compounds into the water. This is why they get attacked with filamentous algae so quickly in containers.
The large monocot plants, (emergent graminoids), like a lawn, are ravenous feeders of nitrogenous matter (anyone who has tried to use lawn fertilizer knows that the first number is N and is usually a double digit number, while the P and K are single digits), which is yet another reason why it is SO important to have Aldrovanda in close proximity (within a few inches) to the roots of these monocot plants) so that they quickly absorb and assimilate these released excess nitrogenous compounds, which in turn, causes these monocot plants to go into over-drive as they process these compounds, by means of respiration and the Krebbs Cycle with the ADP-ATP and all the other chemical functions driven by these processes which result in an increased rate of respiration and the release of CO2 into the water which the Aldrovanda needs for it's accelerated rate of growth for photosynthesis, and to support its amazing growth rate of producing 1.2 to 2.3 whorls a day, and branching every 5 to 7 days, doubling its population exponentially.
This is why Aldrovanda gets SO quickly attacked by filamentous algae (the opportunists as they are) when we try to grow them in containers without these monocot companion plants to quickly remove these excess nitrogenous compound that they release into the water.
The second part of this symbiotic relationship is the host of the zooplankton community that they have dwelling around them. I once took a handful of these plants to my son's college ESU, (East Stroudsburg University), in his Biology preffersor's lab, and observed them under a dissecting microscope, and noticed that they looked like a tropical rain forest canopy in miniature, teaming with life, from rotifers, to several different copepods, paramecium, small snails small worms, insect larvae etc, swarming all over these strands some even grooming and feeding off of the filamentous algae on the strands and some getting trapped in the traps. The small snails were pulling out the spent prey from the old traps which, otherwise would become infested with algae, which is the very base of the aquatic ecosystems food chain.
It was an amazing sight to observe! They actually also function as effective predators to the zooplakton community so that they don't go into those catastrophic cycles of population blooms and busts, going from eutrophic to oligitrophic cycles that eventually developed into severe and massive algae blooms which deplete the dissolved oxygen (DO) from the water during the night so hard, that it kills even fish and just about everything else that depends on the DO. This may be the first time that a plant is categorized as an effective predator of an animal population!"