What is leftover when a Diatom Decomposes? Silica!
When I got an Ostracod infestation in my fish tank and saw my Tetra eating them, all I could do was learn about the food web. The more I learned, the deeper I realized it was. The smaller I realized it was.
From there I switched to a fully planted "natural" aquarium and got a microscope. I discovered Rotifer, Ameoba, Paramecium, and a kaleidoscope of microalgae coating itself in Silica. So many different organisms, all in my tank. An ecosystem.
Now, I put a sample under the microscope every time I add water to the tank to record the findings. Diatoms are an integral part of helping my tank run, as well as a visual representation of the cycle of nutrients- if I take samples from the upper portions of the tank, I am more likely to find alive, free floating, moving, Diatoms. If I take a sample from the detritis, or debris, I am much more likely to find the dead, empty, Silica shell left behind, ready to be broken down and reused by another plant in the tanks ecosystem.
I find this to be an overall representation of the things I like to focus on such as ecology, diversity, and death positivity.