Possibly the least appreciated of all carnivorous plants,since their cultivation needs are drastically different from terrestrial plants,and the fact that capture is rarely seen, despite the full view of the bladders, nonetheless, for the collector who must have every carnivorous plant he can obtain,these plants make great additions to the collection
As you can imagine the best home for any aquatic Utricularia is an aquarium. For many species, a ten-gallon at least is necessary authough some, because they can get quite large, need a larger aquarium than this, unless you take the time to prune heavily once a week.
A decent filter is needed. It keeps the water clean, and hampers the overdevelopment of algae, power filters are considered the best for aquaria, but rather anoyyingly they do pose a few problems for the Utricularia grower. Floating Utricularia will either get pushed into one corner of the tank, or get sucked into the intake of the filter Which is not good! Submerged Utricularia will also get sucked into the intake,this can be bad for the motor of the filter, and the plant. Box filters are a good choice where the fish load is extremely minimal. It is probably best to use two at the same time, on opposite sides of your tank.
Sand is one of the best substrates for submerged species of Utricularia, but its use in an aquarium is to be cautioned. If fish or other large aquatic animals are present, their activities will continually disturb the sand, leaving the water permanently cloudy. The floating particles of sand will land on the plants and any decorations, leaving the aquarium in a horrible mess and hindering the growth of the plants.
Aquarium gravel may be used, but avoid larger gravels. Submerged Utricularia are naturally buoyant,and will eventually float away from the substrate if it is too large. Ultimately, the best sized gravel consists of rocks about 1/4" in size on average.
Either sand, gravel,or a bare bottomed tank is sufficient for floating species, obviously. Do not use peat moss in an aquarium, unless you have it contained in the filter. Many folks put the moss in a tied up stocking. Peat moss in an aquarium as a substrate is definetly not the best choice.
Lighting should be medium to strong, depending on species. Many prefer strong lighting for good growth.Try and avoid overly strong lighting for floating species as algae will form too easily in their mats, and may overtake them.
Aquatic Utricularia love warmth! However for a variety of reasons such as algal and bacterial blooms at high temps, and dormancy, the best range would be from between 20-25°C. Below 18°C and the plants begin developing turions. I have read experiments with U. macrorhiza, and have found that temperature and not photoperiod is the key factor to turion production.
Windowsill jars are a very acceptable way to keep floating species (not submerged ones). Once the plants are established, the jars require minimal maintenance, and in fact can be left unattended for weeks at a time. It is the pre-establishment time that is critical. I have found that most jars do best if filled with a generous quantity of floating Utricularia. At the start algae will still occur, but the bladderwort will easily outcompete it if there is enough plant material in the jar.If you don't have a lot of floating Utricularia to start off with,it will require that you be vigilant,until there is enough plant matter to fill a jar 1/4 full, a complete change of water (and I recommend changing the jar as well) once a week is probably the best way to avoid a surplus of algae.The plants should also be rinsed under lukewarm tap water to dislodge dirt.
Whatever the case, watch that a thick surface scum does not develop. This stops the gas exchange between the water and the air that is so critical to a proper mini ecosystem. If this happens, do a complete water change, rinse the plants, and do this as frequently as necessary until the problem stops. If only a thin scum or discoloration appears at the surface of the water, you may be best leaving it there for a time, watching it carefully, of course. I have noticed that, if the problem isn't too severe at the beginning, it often regulates itself eventually.
Rinsed sand,gravel,and peat moss may be used as substrates,or nothing at all.If using peat moss,wet it completely first,and use only that which sinks to the bottom. Any floating debris must be removed.Take care not to knock the jar once the plants are introduced,or else the peat will swirl all about the jar,much of it landing on the plants.
Keep the jar at a bright windowsill all year long.It is best not to change it's location during the colder months.Recovery from this disturbance can be slow and could threaten the system.
The joys of growing them
When properly cared for,aquatic Utricularia make interesting and often beautiful decorations for the aquarium,or an interesting conversation piece in the jar! Many tend to grow rather quickly,and can turn your aquarium into a veritable jungle.In any case,they are carnivorous plants,which in itself makes them a wonder to be admired,even if they are less than obvious about it
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