Spore Clouding for Farming Uses
Spore Clouding, outside of communication usages, was also used to seed shallow waters with new algae spores. The algae was an incredibly important part of the Koralian's ecosystem, and the Koralians relied on it for sustenance, and for communication.
As such the Koralians encouraged its controlled growth and often seeded and grew large farms of the algae that would float on large surfaces of water where they could get the most sunlight for photosynthesis. Hundreds of thousands of these farms existed across the vast oceans and seas of the Koralian homeworld.
I think communicating through air bubbles is really neat. I like that people could potentially learn to rad it (though sad that they are dying out). I also like how you came up with two very different forms of communication that function using the same anatomy.