Botanicals are a real buzzword right now and they’re used in everything from herbal remedies to Gin.

In short a botanical is a plant or part of a plant that is used for its therapeutic properties, scent or flavour. With herbs being the most famous botanicals.

But in the last few years, the botanical properties of some plant leaves and seed pods have given rise to their use in freshwater aquariums, where they not only release tannins into the water, they make novel, super realistic decoration too.

Take a walk next to a river, lake or natural pond and the margins will not only be littered with wood and twigs, they’ll also be full of leaves, nuts and seeds, and these also play a crucial part in food webs, breaking down and providing food for tiny invertebrates which go on to feed fish. 

Fish and shrimp in turn graze on larger leaves, hide in amongst them and may even spawn on them, with many catfish species like Chaca and Banjo catfish adapted to look just like leaf litter. So add leaves to your tank and you may be adding grazing, hiding and even spawning sites from just one product, as well as make any cryptic, camouflaged fish species feel right at home. 

Add the herbal properties that some botanicals release into aquarium water and you have super decor, which can be just as valuable in some ways as live aquatic plants.

What’s available?

With nearly 400,000 plant species growing worldwide the potential for aquarium botanicals is massive, but not all plant leaves are safe so stick to those for aquarium use only. Try Mango or Cashew leaves. Coconut shells are brilliant for breeding dwarf cichlids like Pelvicachromis and Lotus pods and Bamboo leaves will give an Oriental look and feel to South-East Asian biotope tanks.

Leaf habitats aren’t just the realm of South American, Amazonian biotopes either. White Cloud Mountain minnows, Crystal red shrimp and Paradise fish come from streams that are lined with bamboo, so it makes sense that Bamboo leaves will make up a key part of their habitat and its ecology.

If you want something more conventional go for a mix of Natural leaf litter, which has been tried and tested in aquaria for generations and will quickly stain the water brown, making it ideal for Chocolate Gourami, Cardinal Tetras and Altum Angelfish.  

Or Indian Almond leaves, also known as Catappa leaves, which are great for shrimp and Siamese fighting fish. Many fish farms use Catappa leaves for their anecdotal antibacterial properties. Guava leaves are gaining lots of traction with freshwater shrimp keepers too as they form a biofilm as they break down which shrimp graze on. 

What you need to know about adding botanicals to your aquarium

Be aware that botanicals don’t behave like standard, inert aquarium ornaments. They may float when first added to the tank, and they may stain the water. Once soaking in your warm, bacteria-rich aquarium water they will start to break down, and that process can also deplete oxygen levels. Slime molds and fungus are natural as they consume what is left of any nutritious plant material, but they too can deplete oxygen levels in the water. 

Leaves may also get stuck to strong filter inlets and uneaten food may gather underneath them and decompose. This is of course all-natural, but don’t add lots of botanicals all at once, monitor pH and ammonia daily, and ensure there is plenty of oxygen in the tank, ideally from an airstone or a filter venturi. For best results boil botanicals before using in the aquarium or soak them long term in a bucket of freshwater, outside.

Why do my botanicals float?

Botanicals arrive in a dry, dehydrated condition and will often float for hours, days or even weeks, depending on their cellular make-up and state of decomposition. This is natural, can look very natural, shading out excess light and also providing potential anchors for bubble nest builders like Gouramis. 

If you want them to sink faster than they would normally then again, boil or pre-soak them first, or even hold them down with aquarium plant weights. Floating seed pods can be glued or siliconed onto stones to make them go down and stay down straight away.  Add activated carbon to your filter if you feel the staining from the tannins is too dark.