Algae growing in terrarium, on orchids...okay or bad?
 

I noticed algae growing in the bottom of the terrarium, among the hydroton media. Ive used bleach water before to kill it. However, its growing on the orchid mounts, and pots.

Terrarium is mostly enclosed at top, with 2 fans inside running 24/7. Humidity is provided via a fogger. Bright LED light, as well as direct western sunlight in the afternoon. Daytime temp around 80f.

I have noticed that there is a...musty (?) smell when I open it. I thought this might be due to the algae. So, is this stuff worthy of concern, eradication, or is it harmless? If I need to get rid of it, what would be the best course of action?

Picture included is one of the mounts, as an example.

Is the terrarium bioactive?

The algae isn't a problem in itself. At high humidities like that watch for fungal problems, so be sure air circulation is good. Might you be fertilizing more than necessary?

It is not bioactive. No fungus, but I'll keep an eye on that. I've been fertilizing a bit more than i typically do, to promote healthy growth and flowers, but perhaps I should cut back some.

adding some springtails might help with your concerns about fungus- there is a different scent between musty and moldy but it changes really quick.

the sunlight is also increasing the growth of the algae so there is a balance between the light intensity for the plants and to promote the algae as well... that's not really an answer to any question but it is important to consider