Onion Plant

Water Onion

Picture of an Onion PlantOnion PlantCrinum thaianumPhoto © Animal-World
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Will the water onion be OK with a Betta? Can the bulb be left on the top of the tank to grow?  Belle

   The Onion Plant is a great and hardy plant for many aquariums because it's leaves are extremely tough, making it suitable for aquariums with larger fish!

Onion Plants are easy to care for and adapt well to most aquarium environments. They can grow to an impressive height of 60 inches (150 cm), with their leaves being about 0.8 inches (2 cm) across. Their leaves are extremely long and ribbonlike, and will start growing along the surface of the water once they reach it. Once they are well established you can cut the leaves back some to keep them from growing too long. Because of their height and long leaves they make great background plants for aquariums.

As long as the light is kept moderate to bright, Onion Plants will expend a moderate growth rate. As stated above, they adapt easily to most environments, so as long as the water is kept fertilized with nutrients, the water is cleaned on a regular basis, and the ph is kept around neutral, this plant should thrive. It is also relatively easy to propagate by simply planting the daughter bulbs that are produced.

For more Information on keeping a planted aquarium see:
About Planted Aquariums, Adding Aquatic Plants For a Healthy Aquarium

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Distribution:    They originate in Thailand.

Water conditions:    Temperature: 72-86° F (22-30° C)
   pH: 5.5 - 7.0
   dCH: 2-10

   Light level: Moderate to Bright

Propagation:    The Onion Plant propagates by way of daughter bulbs.

Availability:    Onion Plants are readily available.

Author: Jasmine Brough
Lastest Animal Stories on Water Onion Plant

Belle - 2015-09-29
Will the water onion be OK with a Betta? Can the bulb be left on the top of the tank to grow?

  • Clarice Brough - 2015-10-04
    The Betta should be fine with the plant. They are bulbs, so should be planted in a substrate, but their long leaves will grow to the surface and trail along it.
John - 2015-03-11
I have a heavily planted 55 gal aquarium with approx. 48 fish, cory's, cherry barbs and harlequin rasboros. I have a power filter rated for 70 gal tanks but have not changed the filter medium in years with zero ill effects, it is an extremely healthy tank. The filter is starting to get a little noisier and is likely on its last legs. I wonder if I should reinvest in another filter of the same type or since it doesn't require filter media changes for a healthy tank, should I just put in a powerhead for water movement. I also have two robust bubble bars that produce a lot of water agitation.

  • Clarice Brough - 2015-03-11
    Wow, you have a wonderful biotope in your aquarium. Sounds like the plants, fish, decor, and possibly the filter media are all working together nicely to keep your tank in great shape. So what to do when the filter motor may be going out is a good question. The media in the filter may be very rich with nitrifying bacteria, which may be helping to keep your tank stable. If that's the case, maybe get the same type filter and keep the existing media... But if you think the media is not contributing to the tanks stability, then loosing the filter may not have an effect. Really hard to say! Personally, between your two choices, I would get a new filter rather than relying on water movement alone for water quality. Generally the old media is replaced, but doing that does take out bacteria and so colonies have to re-establish in the new (takes about 6 weeks). But on the other hand, bacteria lives on all the other decor in the tank as well. So it's really hard to say what consequences there will be in either case with a tank that is as well balanced as yours!
jordan - 2012-06-03
So I planted some Water Onion bulbs a couple of days ago and on some of the bulbs there is some white cloudy stuff starting to appear and I wasn't sure exactly what that was? Should I remove the bulbs? Is this dangerous to my fish? Any information would be helpful and thank you in advance!

  • alex - 2014-04-05
    The white cloudy stuff is probably mold?
  • tracy - 2014-12-28
    does it resemble a blister/bubble? if so, i think it's okay. just means that it's growing :)
alex - 2011-06-26
I bought some moneywort from petsmart, and a leaf of onion plant made it into the bag (and my tank), do you think this will grow?

  • Charlie Roche - 2011-06-27
    Might as well try. Usually they propagate via the offshoot bulbs. I have no idea if a leaf can actually root but no reason not to try. Right?
  • Alan - 2014-03-28
    If you haven't got your answer. NO... The leaf will not produce roots with this plant.