Oak Leaves

Todays crop: a box of dryed oak leaves

Dead leaves are beneficial to the home aquaria in many ways. I'm using oak leaves myself and as this is the season to be picking them I thought I would write a quick post about them.

Why Leaves

The benefit of using leaves in the aquaria are many and there is plenty information available on this subject, I will shorty highlight some of them below.
Looks
Many of our aquarium fishes come from habitats littered with leaves. Heiko Bleher himself mentioned how he knew that he would find Apistogramma species in a leaf litter habitat (MaxiZoo talk, Dublin 2013). Oak leaves are a great way for any aquarist that wants to try to replicate such a habitat and it does usually look great.
Biotope/breeding
Tannins released from the leaves helps lowering the pH and stain the water to a tea-color. This further replicates the habitats of many blackwater species. Replicating the natural habitat in this way will significantly increase any breeding attempts.

Hiding

Leaf litter provides an abundance of hiding spots for fry and adult fish alike which adds to the general wellbeing of the fish. In a breeding tank leaves can be the difference between a good survival rate of fry or an unsuccessful attempt.

Food source

The leaves are also beneficial to the growth of fry as they provide an environment for microorganisms on which many fry feed. I often use oak leaves in my rearing tanks and lately a batch of Hypancistrus debilittera were grazing eagerly on the leaves, the batch grew very well and I contribute part of that to the constant availability of food, deriving from the leaves.

Preparation

I have only used oak leaves and can only comment on them.
Collection
Pick clearly dead/dry leaves of a species you know is aquarium safe. Pick only leaves that have already fallen to the ground. Avoid leaves from a polluted area, rotting, exhibit fungi growth or anything else you are not sure about.
Storage
Store the leaves in a dry area, I use an open card box for this purpose. Do not store them in plastic bags or sealed container until you are certain that they are completely dried out. Pick out any “bad” leaves prior to use. I usually dry the leaves for at least a month before use.

Use

Adding leaves
Add the leaves gradually, you will get familiar with how much leaves you need and how they affect the color of the water. The leaves will decompose over time, you can either leave them as they are or if you are afraid of leaf matter clogging the filter/spoiling the looks; siphon the smaller pieces out while performing a water change. Just make sure that you don’t siphon out your fry, in a set up with leaf litters fry can often go unnoticed from view.

Fish species
The effect the leaves have on the water makes them suitable for blackwater species. Personally I use oak leaves in tanks with species of Ancistrus, Corydoras, Hara, Peckoltia, Pelvicachromis and various tetras. Make however sure of what conditions the particular species you keep needs before planning the tank.