You might have heard rumors among planted tank enthusiasts that Anubias can be grown out of water.
Well, it’s true! Anubias can be grown out of water, but only when their perfect growing conditions are met.
If you’re interested in growing Anubias in a half-full aquarium, terrarium, or vivarium, you’re in the right place to learn how!
So, Are Anubias Really Aquatic Plants?
Anubias can be classified as aquatic plants because, although they are not bound to live underwater, they’re able to tolerate long periods or even permanent submergence underwater.
In the wild, Anubias grow on the banks of streams, on rough rocks, or dead wood in humid, tropical rainforests of Central and Western Africa.
They are only sometimes fully submerged in water. Understanding their natural setting is useful for providing Anubias with the ideal growing conditions for them to be at their very best.
The Ideal Growing Conditions for Growing Anubias
Anubias are jungle plants, growing around the forest floor underneath the tall canopy of trees above them. In other words, they don’t receive much direct sunlight in their natural setting.
This is good news for most aquarium owners since you don’t need to go out and buy super-powerful bulbs to successfully grow Anubias. In fact, they will often grow better under slightly dimmer light conditions.
Their preference for subdued lighting also makes them an ideal choice for fish that prefer the same conditions.
Fish that inhabit the streams and pools of rainforests such as betta fish, chocolate gouramis and paradise fish can all be kept successfully with Anubias.
Since Anubias can grow emersed (out of water) we can conclude that they can obtain most of their nutrients from their roots.
But Anubias don’t need a very rich substrate to thrive and can do well anchored onto anything from aquarium gravel to aquarium sand, tied or glued to rocks or driftwood, or grown in aquarium soil.
Because it is a slow-growing plant, researchers have experimented with different substrates to find out in which one Anubias grows fastest.
A scientific study in 2020 revealed that Anubias grew faster in sand than in husk charcoal, gravel, or rock wool. But the growth rate will also depend on the amount of nutrients such as nitrates and phosphates, and CO2 in your water.
The most important thing when planting Anubias is that you don’t bury the horizontal root stem. This horizontal rhizome needs to remain above the substrate where it will put down fine roots into the substrate to gain its nutrients.
If the main stem is buried, it may die off and rot.
Since Anubias come from near the equator, they thrive best in warm conditions. Water temperatures between 73-80°F are ideal for most species.
Amazingly hardy, Anubias are unfussy when it comes to water parameters. They’ll do fine in a pH of anywhere between 6-8, and a water hardness of between 5-20 dGH should be fine.
These water preferences make Anubias suitable for almost all types of tropical freshwater aquariums, so long as you keep them with compatible fish!
Suitable Fish To Keep With Anubias
The tough, leathery leaves of Anubias make them an ideal plant companion for all kinds of fish, even those that may eat more delicate plants such as those of the Limnophila genus.
Community tank fish such as tetra, barbs, and angel fish will all cohabit a tank perfectly well with Anubias, and these robust plants have even been known to stand up to boisterous, plant-eating fish like African cichlids!
Some goldfish or Oscars, however, will simply dig up and rip apart any plant that you put in their tank, meaning that not even Anubias are totally fish-proof!
Can I Keep Anubias as a Houseplant?
Anubias are beautiful plants to look at. When I discovered that Anubias can be grown out of the water, I wondered whether I could keep some in pots as house plants.
Sadly, they need an incredibly humid environment to thrive, meaning Anubias won’t do well as house plants unless, perhaps, you live in the tropics!
Can I Keep Anubias in a Terrarium or Vivarium?
Since Anubias don’t need to be submerged in water to grow, they can grow in terrariums and vivariums so long as there’s plenty of water in the substrate and a tight-fitting lid to maintain a humid environment.
If there’s not enough water either in the substrate or in the tank’s atmosphere, the Anubias may wither and die.
Does Anubias Prefer Growing Out of Water?
Some people have concluded that as long as there is a humid environment, Anubias prefer growing with their leaves and stems out of the water. In reality, this may depend on the species and their natural habitat.
We must remember that Anubias is a large genus of plants including popular species such as Anubias hastifolia, Anubias barteri, Anubias Nana, Anubias gigantea, and Anubias afzelii.
Each one of these will have its own unique habitat preferences, but, in general, Anubias are incredibly hardy plants that can grow fully submerged in water or with their leaves in a very humid environment.
How Long Can Anubias Be Out of Water?
As we discussed, Anubias can be kept in terrariums and vivariums without being submerged in water, but in the much drier environment of your home, the leaves could begin to wither and die.
If you need to move your Anubias out of the water for more than 10 minutes during aquarium maintenance or to move them, it’s a good idea to keep them in zip-lock bags or another type of air-tight container so that the leaves remain wet, fresh and vital.
Do Anubias Need CO2?
Like all plants, Anubias need carbon dioxide to photosynthesize. But do they need carbon dioxide injection to make the aquarium water richer in CO2?
As one of the toughest aquarium plants, Anubias don’t need carbon dioxide injection to survive. But that’s not to say that CO2 injection wouldn’t boost their growth rates!
If nutrients, lighting, and temperature are all-sufficient, then the level of CO2 could become the limiting factor for their growth rate. Some aquarists have indeed reported that their Anubias grew faster and with thicker leaves when given extra CO2.
But another way of providing your Anubias with plenty of carbon dioxide is simply to let some of their leaves grow out of the water.
In the humid air at the top of the fish tank, your Anubias can obtain more CO2 than in the water, meaning they may grow faster when only semi-submerged because of the extra exposure to CO2.
Do Anubias Need Fertilizers?
Since Anubias are slow-growing plants, they’re not very likely to need extra fertilizers in a typical aquarium.
The nitrates and phosphates released from your fish waste and uneaten food, and the minerals in your tap water, are likely to be sufficient to feed your Anubias without the need for root tabs or aquarium liquid feeds.
If you’re keeping your tank immaculately clean and using very effective carbon filtration, however, it might be wise to test your water using an API kit to make sure there are adequate nutrients for your live plants.
Why Do My Anubias Keep Dying?
The number one mistake that fish keepers make when planting Anubias is burying the horizontal stem into the substrate.
As I mentioned earlier, this thick, rhizomatous stem must always stay above the sand, gravel, or aquarium soil to remain healthy. If it is buried it will rot.
This is not to be confused with ‘Anubias rot’ – a rare disease caused by bacterial or fungal infections that cause the stem of Anubias to rot even when grown above the substrate.
Although scientists still haven’t found the exact cause or treatment for Anubias rot, it’s advised to cut away the rotten portion of the stem to prevent it from spreading to the healthy part. With luck, that will be enough to curtail the disease in most circumstances.
Anubias are one of the most robust and unfussy of all aquarium plant families and can grow just as happily out of water in a humid environment as when fully submerged.
If you want to grow Anubias out of the water, you’ll need to make sure you have a tight-fitting lid and a heated tank to maintain the warm, humid environment that this plant loves.
To see our care guide for the extremely popular Anubias Nana ‘Petite’, click here.