Hobby XL catappa leaves for aquariums, pack of 12
This pack contains 12 large Hobby leaves from the tropical almond tree, Terminalia catappa, which give a freshwater aquarium the amber water of a natural biotope.
They release tannins as they break down, and provide a surface for microfauna and shrimp.
The summary
- What you receive: 12 large whole Terminalia catappa leaves.
- What they do: they release tannins as they break down, and tint the water amber.
- Usage guide: 1 leaf per 50 to 100 litres.
- Replacement: every 3 to 4 weeks, once the leaf has broken down.
- Who it is for: a freshwater tank, shrimp included.
- Shipping: small flat parcel, sent together with the rest of your order.
Pack of 12 Terminalia catappa leaves, for amber-tinted biotope water
The Hobby XL catappa leaves, sold in packs of 12, come from the tropical almond tree Terminalia catappa and give the water of a freshwater aquarium an amber, biotope tint. As they break down, they release tannins. Allow 1 leaf per 50 to 100 litres, replacing it every 3 to 4 weeks.
These 12 large Catappa Leaves XL from Hobby come from the tropical almond tree Terminalia catappa, also known as the Indian almond. Placed in the water, they break down slowly and release tannins that tint the water a light amber, like the blackwaters of South-East Asia. You are receiving a dried natural product, so no leaf is exactly the same size or thickness as its neighbour, and each one breaks down at its own pace.
🍂 What the leaf releases
Tannins are acidic organic compounds that the leaf releases as it softens. They tint the water light brown and help to lower the pH slightly, which brings the aquarium closer to a blackwater biotope. The extent of this drop depends on carbonate hardness: in soft, poorly buffered water, the pH reacts markedly, whereas hard water absorbs the acidity and the pH barely changes. If you filter through activated carbon, it retains some of the tannins and the colouring fades.
Measure the pH before and after the leaves
The pH drop test kit tells you by how much your water's pH has changed after adding the leaves, which lets you adjust their number rather than guess. Take a reading before the first leaf, then another a week later, and the article on pH regulation explains what keeps this parameter stable in a living tank.
Colour
The water takes on a light amber tint, which deepens with the number of leaves in the tank.
Tannins
They help to lower the pH slightly, especially in soft water with little limescale.
The microfauna
It colonises the decaying leaf, and the shrimp come to graze over it to feed.
🔁 Dose and renewal
Allow 1 leaf per 50 to 100 litres, and replace it every 3 to 4 weeks, once it has broken down well. A dry leaf often floats for several days before sinking, whereas a few minutes in boiling water makes it sink straight away. With 12 leaves per pack, a 100-litre tank will last almost a year on a single purchase, and you can keep the leaves dry in their box until their turn comes.
The number of leaves determines the intensity of the colour, more than the length of time they are in the water. So start with a single leaf, watch the tint and the pH for a week, then add a second one if you want a more amber-coloured water. A leaf in tatters has already released most of its tannins: remove it, or leave it for the shrimp, which eat the remains, then add a new one.
🌿 Biotope water
Catappa leaves are used above all in tanks that recreate the soft, acidic fresh waters of tropical forests, where fighters, gouramis and rasboras live naturally. They are laid on the substrate, between the plants or against an aquarium root, which also releases tannins and completes the natural look of the décor. To monitor your water's hardness before aiming for an acidic biotope, the KH carbonate hardness test shows your water's capacity to absorb this acidity.
Technical specifications
The essentials
- Quantity
- 12 whole sheets, XL size
- Species
- Terminalia catappaThe tropical almond, also known as the Indian almond tree.
The usage guide
- Coverage
- 1 sheet for 50 to 100 L
- Water changes
- Every 3 to 4 weeksWhen the leaf has properly broken down.
What the water becomes
- Colour
- Light amber
- Effect on pH
- Slight drop
To budget for separately
- pH monitoring
- A pH test
- Weighting or scalding
- To make a dry leaf sink
In the box
- 12 whole Terminalia catappa leaves
Usage guidance and replacement schedule recorded on 20/09/2026 from an aquarium-keeping guide; contents of the pack taken from the Hobby box.
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Dispatched as a tracked parcel from France, and can be combined with the rest of your order. The exact charges and delivery times are shown at the basket once the address has been entered. Outside the European Union, import duties and taxes are payable by the recipient.
Frequently asked questions
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