Linda's tank is similar to Danh Ngo's tank. A major portion of it is colonized by dozens of RBTA's.
Both tanks are very well established. They can handle any large pollution problem that comes along. If it were were me, I wouldn't give it a second thought. In fact, I'll bet it's back to normal today, with no evidence of yesterdays spawning. Removing the large rock, breaking it up and removing/chiseling off those RBTA's caused a change that initiated the spawning. It's all good.