Aquarium professionals and hobbyist have used Catappa, or Indian Almond leaves for many years, and various types of aquarium creatures. It turns out they have many properties that can be an excellent boost to your shrimp aquarium.
Why are Indian Almond leaves beneficial for your shrimp? They release tannins that have antifungal and antibacterial properties that can prevent your shrimp (and fish) from being susceptible to illness. They also have a surface where biofilm can thrive which will provide a healthy food source for shrimplets.
let’s take a better look at the benefits and how to best use the leaves in your aquarium.
Benefits of the Catappa Leaves
Antifungal and Antibacterial Tannins
In nature, a tree puts in the antibacterial and antifungal properties in its leaves to make sure the tree has a healthy leave to growth. When you put the leaves in the water, those same antibacterials and antifungals get released into the water. It is beneficial for your shrimp (and fish) just being in the same water.
Extra Biofilm Surface
Biofilm is a collection of bacteria, algae, fungi and other multi-cellular organisms that form a layer on the surface of everything that is in your aquarium. It forms a coating on the plants, the glass, the hardscape and the sponge of your filter. On the leaves, when they are submerged in water, the biofilm has a lot of extra surfaces to grow. These microorganisms will develop and consume and breakdown the leave and, at the same time are a food source for your shrimp. The biofilm on these leaves combined with the particles of the leave itself breaking down will have all the right nutrients of the biofilm and the leave combined. This biofilm surface is, therefore, an excellent food source for your shrimp and shrimplets. Especially for the little shrimplets that still have a problem with the larger food particles you feed your adult shrimp.
In general, shrimp love to eat biofilm

Trace Elements
When leaves break down in your aquarium, it also releases trace elements and different things in the water that are beneficial to fish and shrimp, even if they wouldn’t consume the biofilm and the decaying leave.
A Place to Hide for Schrimplets
Shrimp and shrimplets and fish fry like to hide from time, especially when shrimp have just molded and are very vulnerable, they want to protect themselves by hiding until their shell has hardened again. The Leaves provide an excellent hiding place for them.
Catappa Leaves Lower pH
The breakdown of organic material in your aquarium will lower pH. You won’t suddenly drop the pH or decrease it by a significant amount, but you will be able to measure it. A buffering substrate can compensate for the gradual drop in pH in the tank or by adding thing like a bit of crushed corral if your wat to maintain a certain level of acidity. Using the Catappa leaves in small numbers, one or two at a time in a 10-gallon aquarium or larger won’t make much of a difference. In larger quantities, they can be used to lower the pH when desired, but for this, a little peat moss in a bag in your tank or filter will be more effective. Caridina shrimp generally like a little bit lower pH (depending on where they are from, 5.8 to 6.9) than Neocaridina (6.5 to 8) but they both will not show any adverse effect when you are not using them hands full at a time.
Usually, the shrimp won’t mind these little gradual changes, and the benefits outweigh this side effect by far in my opinion.
It will take about two weeks for the leave te start breaking down. Depending on how many shrimp and snails, it can take about two months until there is nothing but the skeleton (leave vanes) of the leave remaining.
How Many Indian Almond Leaves per Gallon?
One leave once a month per 20 gallons. For example, if you have a 10-gallon tank, use one, or half of one. In a 40-gallon tank, you can use two leaves per month. I would advise, in this case, to put in one every two weeks and not two at the same time, once a month or you will have a chance to spike the nitrates, which your shrimp won’t like. You can vary this a bit, and if they don’t break down in this time, you can wait a little longer before you put next Catappa in. If you have a lot of shrimp and fish, you can give them a bit more. You will develop a feeling for this soon.
If you don’t like the sight of the big leaves in your tank, you can break them up into smaller pieces and scatter them behind some plants or rocks.

How to Prepare Almond Leaves for Your Shrimp Tank
You don’t need to do anything special to use the leaves. You can use them right away, pop one or more of them in your tank and you’re done. I would give them a quick rinse under the tap to get rid of dust and loose particles. The leaves will release tannins, coloration, in the water. Tannins are very beneficial for your shrimp and fish. Tannins are antifungal and antibacterial, but it can make your water the color of a light tea. If you don’t mind this, great, but if you do, there are some things you can do to reduce this effect.
You can pre-soak the leave a couple of days till they have given off some of the tannins. This will reduce the coloration quite a bit. The advantage is that the leaves will sink to the bottom right away when you use them in your aquarium. If you want to get rid of almost all the tannins (and most of the beneficial properties), you can boil the leaves before use. This way, like tea you can cook all the coloration out of the leaves.
How to Keep the Catappa Leaves Submerged
When you buy them, the Indian Almond leaves are usually dried, for easy storage and long-term preservation. The fact they are dehydrated will prevent them from sinking to the bottom when you want to use them. There are a couple of things you can do to keep the leaves submerged:
You can Boil Them
Boiling the Almond leaves will get them waterlogged fast. It will also make them release most of the tannins. If you place a high value to a crystal clear water tank, this is your best option. This way, your shrimp can still benefit from the biofilm and the trace elements in the leaves, and you won’t get a slight tint in your water. The downside to this is that you will boil out most of the Antifungal and Antibacterial properties of your leaves.
You Can Put a Stone on Them
Weighing them down with a heavy object will keep them submerged until they are enough waterlogged to stay down by themselves. Eventually, the leaves will remain down, but if you don’t want to wait for this, or you don’t want random chance determining where your leave will end up, this can be a great option.
You Can Stick Them in the Substrate
Usually, the leaves will still have a little stem where they were attached to the branch they grew on. You can use this small piece to stick the leave in the substrate or wedge it in between a bit of hardscape if you have any.
You Can Wait Till it Sinks
By far, the easiest thing to do is just put it in the tank and wait till it sinks by itself. In the aquarium, the leave will, and when it is waterlogged, it will fall to the bottom. It will usually take a couple of days for the leaves to sink.
Do I Need to Use Indian Almond Leaves
You don’t need to put leaves in your shrimp tank, shrimp are hardy creatures and can live comfortably in less than ideal circumstances, but they will benefit a lot if you do. It is one of those extra things you can give your shrimp that can make them thrive in your tank instead of just surviving.
Related Questions
Will Snails eat Indian Almond Leaves? If you have snails in your aquarium, the snails will enjoy the benefits of the Catappa leaves. They will also help break down the leave. Even when the snails have digested the leaves, their poop will be full of beneficial nutrients and be good for your shrimp.
Will tannins harm fish? The tannins will not harm your fish, they are full of Antifungal and Antibacterial properties, and fish will benefit as much as your shrimp from these.