Not sure how many of you are familiar with the saltwater coralline algae? This algae is quite unique as its cell walls actually contains calcareous deposits, enabling this organism to actively help build reef structures.
In my aquarium I make sure to dose alkalinity supplements (Sodium Carbonates mainly) and maintain high Calcium and Magnesium levels. Together with strong illumination (500W of metal halides), I manage to have coralline algae cover the whole back panel of the aquarium.
Here are some photos. They are hard to photograph because they are thick and almost opaque. Also, they are very brittle so getting a sample is not easy.
40x, DIC, 69 image stack using Helicon Focus method C
40x, BF, 36 image stack using Helicon Focus method C
and my favourite... Showing the calcareous cell walls clearly.
40x, POL, 23 image stack using Helicon Focus method A.
Images made through a microscope. All subject types.