In October of 2021, I set up 2 saltwater aquariums. One of the aquariums is a 29 gallon "mixed reef" tank and the other is a 10 gallon "coral quarantine" tank. I started each aquarium with dry rock from my local fish store. After researching, I came to the conclusion that I would cycle the aquariums with live corals because I found that they would not die when cycling the aquariums and would help establish biodiversity in the tanks. Two corals I received, both leather corals, were attached to some rubble rock that contained 1-2 small spots of bubble algae. After growing these corals for little over a year, one in my coral quarantine and one in my 29 gallon tank, I noticed the bubble algae had grown significantly in my 29 gallon tank in many different parts of the tank but in my coral quarantine, it had just grown on the same rubble rock and had not spread throughout the tank. What had I done differently? In my display tank, I manually removed the bubble algae from the rubble and siphoned it out. I thought it was coincidental. So, for science, I went into my coral quarantine tank and manually removed it from the rubble the leather coral was attached to. Fast forward one month- the two pieces of dry, now live-rock in the coral quarantine tank now had some significant bubble algae growth. We have found the bubbles don't release spores when being popped, so how did agitating the algae help it spread? If it was a coincidence, I'll post an update in a few months because I just set up another 10 gallon tank and I am going to conduct the same experiment.