Can black algae be contagious when placed near black algae.

[Mazain]

I have a Driftwood with black algae placed in the mid section of my tank. Crypts, Hygrophila Corymbosa and Siamensis are placed near it and the plants are free of any black algae.
Will black algae form on those plants since the Driftwood is next to them?

 

[TwoTankAmin]

Contagious is the wrong term.

Algae regenerate by sexual reproduction, involving male and female gametes (sex cells), by asexual reproduction, or by both ways.

Asexual reproduction is the production of progeny without the union of cells or nuclear material. Many small algae reproduce asexually by ordinary cell division or by fragmentation, whereas larger algae reproduce by spores. Some red algae produce monospores (walled, nonflagellate, spherical cells) that are carried by water currents and upon germination produce a new organism. Some green algae produce nonmotile spores called aplanospores, while others produce zoospores, which lack true cell walls and bear one or more flagella. These flagella allow zoospores to swim to a favourable environment, whereas monospores and aplanospores have to rely on passive transport by water currents.

from https://www.britannica.com/science/algae/Reproduction-and-life-histories

Basically, you can think of algae like a plant, except aglae actually competes with plants. But understanding how and why algae may be an issue in one tank and not in another is more complex that how they reproduce. The basic wisdon in the planted tank world is that the right plants and proper care thereof will result in the plants out competing the algae for nutrients. And this holds down algae.

I do two types of tanks- planted comminities and unplanted pleco breeding tanks. The planted tanks vary, some have little alage which is never an issue and others I have been battling alage for years. However, My pleco breeding tanks only have a light on when I amd woring in the tank. Moreover, the room with most of these tanks has almost no light during the day. There is only one window and it has nlind on it which is down all the time. I have almost no algae in any of the tanks in this room.

Algae thrives when it can get all the light and nutrients it needs to do so. Some hobbyists want some algae in tanks because they keep algae eating fish. Such folks will be happy with algae on the back glass but not so much on the front. Excess nutrients or an imbalance of them in a planted tank as well as excess light are the primary causes of algae being able to thrive or overwhelm a tank. Think of algae as being opportunistic in it's ability to thrive.

 

[Mazain]

The basic wisdon in the planted tank world is that the right plants and proper care thereof will result in the plants out competing the algae for nutrients. And this holds down algae.

Thanks two tankamin, so proper plant care holds down the algae.

 

[Mazain]

Thanks to your citation, monospores which is red algae needs water currents. That was actually the answer what I was looking for. In other words I changed the filter inflow to the tank making a zig zag flow from the front wall corner of the glass to the back glass corner like 2 90' degrees triangle shapes. This has actually limited my red algae.