ᐅ What is going wrong with my garden pond?

Three years ago, I built a garden pond myself. It is a simple construction made from thick liner. The pond was quickly inhabited by frogs, newts, dragonflies, and even leeches.

However, everything seems to die off over the winter. In spring, I always have to fish out dead frogs from the bottom. At that time, I also remove the leaves and add fresh water. During the summer, it seems that new amphibians move in again, but they do not survive the winter. What could be the reason? Maybe not enough oxygen?

Hi Johannes! How deep is your pond? To ensure frogs and other amphibians can survive, the pond must never freeze completely in winter. It should be at least 50cm (20 inches) deep!

Do you have a lot of leaves in your garden pond?
I think there was too little oxygen or none at all. When the bacteria in the pond start to break down the organic material (leaves), aerobic or anaerobic bacteria come into play. The latter only act when no oxygen is left. During this process, foul gases are released, which cannot escape if there is an ice layer. As a result, the animals get poisoned.

It can be the case that if there is too much leaf litter or other organic material in the water, the oxygen is depleted and there are too many toxins in the water.

And you probably didn’t make the pond only 20cm (8 inches) deep, so that the entire body of water freezes, because then your frog could die.