That’s not the cyanobacteria’s fault, I think that it is mine, so thanks for pointing that out. In the post-processing I clicked on the microscope slide to white balance because the background seemed too blue. But now that you mention this I think that the bluish hue in the background was realistic and setting it to white removed the blue from the blue-green cyan. Without the white balance the color is more cyan:

Thanks!

I didn’t know about microcystins. Interesting molecules! I think this particular species does not produce them, but I won’t eat them… at least for now. I might grow some edible algae in the future.