Black spot and preventive care

[Steve83]

I have two Catts which have developed some small black spots, as shown in pic.

C.hyb.jpg - Google Drive

Some info I read stated that it is caused by bacteria landing on the leaf via water dripping from another plant, while others stated that it was likely mechanical damage.

Both could have likely happened, given that they are situated in a wire shelf in a tent.

If bacterial, should I be treating it/they and other plants?

I also didn't know if anything like preventive treatments were a part of anyone's culture. The only measures against pests/disease I have in my culture at the moment are a bacteriostatic for the humidifier reservoir, sanitizing tools & potting area, cleaning up puddled water from the mounts, and a sundew which has eliminated some fungus gnats.