I love maintaining my aquarium and I enjoy giving tips to others.
Cultures from northern China to South Africa regard lotus plants as sacred. Red tiger lotus (Nymphaea zenkeri) plants grow astonishingly quickly and are considered an invasive species in many areas of the USA. The growth rate of tiger lotus allows it to soften water and absorb a lot of nitrate and phosphate. One plant will turn 50 gallons of hard water into soft water in a few weeks. However, if you use these gorgeous plants in an aquarium, you will want to take some precautions to ensure that they don't take over.
What Is a Tiger Lotus?
Tiger lotuses are a lily pad. This is surprising to some people because tiger lotuses have arrowhead-shaped leaves instead of the round leaves of lily pads people are familiar with. The red leaves can develop striped variegation under heavy lighting. The red tiger lotus will have royal purple on the bottom side of the leaves. However, if sufficient iron isn't present, the red tiger lotus may produce green leaves.
Tiger lotuses produce highly aromatic blossoms that are usually white. Depending on the species, some varieties will produce blue or red flowers. Many combinations of these colors are available because of selective breeding and hybridization over many centuries and continents.
How to Grow Tiger Lotuses in Aquariums
Red tiger lotuses are easy to grow in aquariums. They develop large root systems and do well with fertilizer in their substrate. Iron-rich clay aggregate is an ideal planting medium.
Tiger lotuses grow extremely rapidly under 3 watts T-5 per gallon lighting. I have yet to determine the maximum size. Mine was larger than many of the maximums stated by others in less than a month, and it continues to grow. These incredibly beautiful plants are deemed pond plants by many because of their extreme growth rate. This growth rate is considered a problem in an aquarium, but the difficulty is easy to overcome.
Overview of Difficulties Aquarists Encounter With This Plant
Unfortunately, the prodigious rate at which these plants grow makes them an invasive species in tropical and subtropical climates. If there isn't a freeze to kill them, they will overtake any slow-moving water system. They are generally regarded as pond plants because of their phenomenal growth rate.
If left to their own devices in an aquarium, they will quickly overtake and strangle out all other plants. Planting them in an aquarium is possible, but if you want to grow it alongside other plants, the tiger lotus must be kept from spreading. Here is an overview of the different problems, followed by how to address each problem.
1. Enormous Root Systems
The first problem is that the root systems can grow to be enormous, and if they do, they will strangle all rooting plants. Therefore, the root system must be contained.
2. Overwhelming Seed Production
The second problem is that the beautiful blossoms produce seeds by the hundreds. To halt the spread of the tiger lotus, you must keep the seeds from being produced, or at least from getting into the water.
3. Massive Growth
The next difficulty that people with smaller aquariums may run into is the size of the plant. Not only do they grow faster than any weed you're familiar with, they get huge. In less than three weeks from planting the bulb, you can expect it to have leaves larger than your hand. It will produce many of these leaves very quickly. The growth rate will then explode as floating leaves (pads) reach the surface.
4. High Nutrient Requirements
Another reason plants may stop growing or die when a tiger lotus is introduced to the aquarium is that the plant extracts large amounts of nutrients from the water to support its growth rate. It will consume nitrate, phosphorus, iron, magnesium, carbonate, CO2, and all other macro and micro nutrients, which can starve many other plants if they are planted too closely.
5. Pheromone Concerns (Myth)
Some people also blame a pheromone for the reduced growth or death of plants. I have not encountered any scientific evidence to support this. Only certain plants that gain most of their nutrients directly from the water are affected when planted inches away from the lotus, discrediting the rumor.
How to Contain the Root System
Containing the root ball will keep the tiger lotus's root system from taking over the aquarium substrate.
This can be done using:
- A plastic container that can hold at least four cups
- A piece of fine nylon mesh fabric that's big enough to wrap the container
- Fishing line
- Four cups of substrate
- A root tab fertilizer
Then follow these steps:
- Fill the plastic container with substrate and a root tab fertilizer.
- Wrap the container tightly with fine nylon mesh fabric.
- Cut a piece of fishing line to tie the fabric: Eight inches will be plenty.
- Bring the fabric together and twist. When the excess fabric is twisted together, double it over itself and tie with fishing line.
- Cut a small hole for the plant to grow out of.
- Place the container in the aquarium. The plastic container can be concealed using large flat rocks and root wood.
How to Control the Seeds
The blossoms will produce seeds, which will create more lotuses. If you want hundreds more, this isn't a bad thing. Fortunately, there are are a few things you can do to prevent having hundreds of tiger lotuses in your aquarium.
- Cut the flowers: You can keep a tiger lotus blossoming for many months by cutting the flowers before they wilt, and turn to fruit. No fruit, no seeds.
- Cut the surface runners: Tiger lotus will not produce blossoms if they have no floating leaves. If you trim the surface runners, no blossoms will be created. Cutting the surface runners will also promote submerged leaf growth and slow overall growth. No blossoms, no fruits, no seeds.
- Use blue and white light: Plants need red light to produce blossoms. If you grow the Tiger Lotus under actinic blue and soft white light, it will not blossom.
Can I Still Propagate the Plant?
If you intend to propagate your red tiger lotus, you can do so in a controlled manner. The fruit of a tiger lotus will explode to disperse the seeds. To prevent the seeds from going everywhere, you can wrap the fruit in mesh and tie it with a piece of fishing line. The mesh will make it possible to grow the seeds in a nursery tank or pond.
How to “Slow” the Growth Rate
I'm using the word “slow” as a relative term. Tiger lotus grows faster than any plant I've ever seen. I hear that lumber bamboo grows faster, but not much else. These plants are considered an invasive species in southern latitudes for good reason. In northern temperate latitudes, they are often labeled perennial and are readily available because a winter freeze will kill them.
The tiger lotus's floating leaves (pads) allow it to access the abundance of CO2 in the air. Water doesn't hold very much CO2, even if you use CO2 injection in your aquarium. If you clip the runners that the plant sends to the surface, then the growth rate will be slower. Cutting the surface runners also prevents blossoms and encourages submerged leaf growth.
You can further slow a tiger lotus's growth by trimming submerged leaves. This will reduce the size of the plant and limit how much nutrients it can absorb. The less nutrients it can absorb, the more slowly it will grow.
Keeping Your Other Plants Healthy
The plant's incredible growth rate is fueled by the nutrients it gains from the substrate and the water. If the roots are contained, other plants with roots systems will be little affected by the tiger lotus. I have Amazon sword (Echinodorus bleheri), Bacopa australis, Rotala nanjenshan, and jungle val (Valisneriaamericana) thriving inches away from the tiger lotus's container. Every week, I trim the Rotala back to half it's size. If plants develop significant root structures under the substrate, they will be little affected by a Tiger Lotus with an isolated root system.
I did have a large piece of root wood thickly covered with Java moss. I used the piece of wood to hide the back of the Tiger Lotus root container (when the Tiger Lotus was small). A few weeks later though, almost all the moss was gone. Moss more than 6 inches away from the plant continued to thrive. From this I surmise that if a plant gains most of its nutrients directly from the water, it should not be place near a red tiger lotus. Keep mosses, anubias species, ferns, and anything that doesn't grow roots under the substrate away from lotuses. Again, my Java moss more then six inches away thrives as if the tiger lotus wasn't there.
Take Good Care of Your Plant
Red tiger lotus can be a wonderful addition to your aquarium if certain precautions are taken. The plant's extreme growth rate is a double-edged sword. It will make a considerable contribution to controlling algae because of its size and growth rate. These same qualities can become a problem if measures aren't taken to prevent its takeover. This is one of the most beautiful plants and the blossoms are intoxicating (though not literally, as is the case with the Egyptian blue lotus). With a little effort, you can prevent the lotus from taking over your aquarium, and you can enjoyably contemplate your thriving plant.
Lea on March 04, 2020:
Will the roots cross sand if I make an island?
Eddie DeMott on April 01, 2016:
My daughter in New York City surprised me. I received a package of 12 seeds from Hong Kong. The package was labeled "Red Nymphaea", nothing more. No instructions. I live in Rochester, N.Y. and have nothing in my gardening library on this plant except one book which uses the term "a lotus plant". I didn't have a clue what to do with the 12 seeds! Your article was a God-sent. Thank you ever so much. Eddie DeMott, Rochester, N.Y.