If you are a budding Takashi Amano, the idea of putting succulents in a fish tank with fish sounds amazing.
After all, this diverse family of vividly colored, fleshy-leaved plants that have weird and zany shapes could be an eye-catching addition to an other-worldly aquatic display.
Unfortunately as terrestrial plants, even with the best conditions, your regular houseplant succulents just aren’t going to survive immersed in a fish tank.
For a succulent display, use a dry tank with separately drained pots; ordinary succulents are not aquarium plants.
In this article, we’ll get the bottom of succulents in the fish tanks.
Can you grow succulents immersed in water?
With thousands of succulent varieties in the world, it’s no surprise that aquascapers would want to cultivate these thick-leaved beautiful plants immersed in a fish tank.
But terrestrial, non-aquatic succulents will struggle to survive if continually immersed in a tank.
Here’s why.
Succulents are xerophilic
Succulents are dry-loving plants known as xerophiles.
They are specially adapted to live in environments that have a very low availability of water.
Hailing from deserts, wildernesses, and other arid regions in Africa, the Americas, Asia, and Australasia succulents are equipped with fleshy leaves with a thick cuticle to store water meaning that they can survive on very little water.
Too much water usually overwhelms succulents, causing them to swell and quickly rot.
Transplanted succulents have terrestrial roots
Though succulents can be grown using hydroponic methods, you can’t just take a soil-growing succulent and immerse it in your aquarium substrate.
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The root system of the succulent is not adapted to growing in water.
The roots will not be able to obtain adequate oxygen and nutrients from the water.
Submerged growing conditions can cause ordinary terrestrial succulents to rot. Do not use water propagation as evidence of suitability for a stocked aquarium.
Do not substitute terrestrial succulents for aquatic plants
Ordinary terrestrial succulents should not be grown submerged in a stocked aquarium. Aquatic species have different requirements; fish compatibility is not established by a plant’s succulent appearance. RHS guidance on succulent growing conditions.
Water propagation does not establish fish compatibility
Water propagation or hydroponic experiments do not establish that a succulent is suitable for a fish tank. Keep terrestrial succulents in their own freely drained containers.
And of course, you could simply grow your succulents in a fish tank without the water
Growing succulents in a large aquarium tank can make a dramatic display.
You can be incredibly creative by using colored substrates, sand, and stones to create layers that are visible through the glass for added drama.
A tank without drainage holes needs removable, freely drained inner pots.
Some gardeners are upping the ante by creating a stunning display with these terrarium-style arrangements.
How to plant succulents in a fish tank
For a dry decorative tank, keep succulents in removable pots with drainage holes and free-draining mix. Remove the pots for watering and let them drain before returning them. Leave the display open for ventilation; do not add fish or standing water. RHS succulent cultivation guidance.
Gravel does not replace drainage
A decorative gravel layer is not a drainage outlet. Choose a growing mix appropriate to the species, and use pots with drainage holes.
Rounding Up
Use ordinary succulents in a dry, ventilated display with drainage. Choose true aquatic plants for a stocked aquarium.