Nymphs in Smallest Self-Sustaining Aquarium Update

Michael Langerman
3 min readJun 22, 2020

Last year I shared some of my fun Summer self-sustaining aquarium projects with you.

And then something else came up after I published the video.

Let’s take a closer look at the 60 ml nurseries here in the middle as they were on July 13th, 2019.

There are a lot of tiny critters and … something that looks like the eggs of some critters.

I keep these nurseries on a windowsill exposed to direct sunlight to grow algae.

Critters feed on the algae and produce waste that algae feeds on.

Covers on top reduce water evaporation.

It’s an example of one of the smallest self-sustaining aquariums I have built.

Eventually filamentous algae started growing in both nurseries.

Here you can see the nurseries about 2 months later on September 27th.

And there are nymphs — a damselfly nymph in each nursery!

Nymphs feed on small critters and other nymphs.

So, it’s not a surprise that only one nymph remains in each nursery.

What surprised me is that they grow about 1.5 cm long in a 60 ml nursery.

They got enough food to grow for 2 months!

Here is a good view of both nymphs.

This one is hunting a seed shrimp.

The amount of critters has been reduced visually in the past months.

I record a timelapse video just to check if there are any more critters.

Certainly there is not enough left to support the needs of my nymphs.

On October 6th 2019, I decide to release my nymphs into a local pond.

Here is a final look at my smallest self-sustaining aquariums with nymphs.

Have fun and happy Summer projects :)