I'd be almost certain it is in your DT right now. It can reproduce by fragmentation, sexually, asexually. It is extremely invasive, and if left unchecked will take over your system.
If you copy and the paste the following into google and you can read all about this invasive algae.
Introduction
One of the most beloved of macroalgae in reef aquaristics are those rare guests, Bryopsis, one of several genera affectionately dubbed ‘hair algae’. Bryopsis are a vital and much sought-after component of the compleat reef aquarium. Bryopsis can cure cancer, end poverty, and bring about world peace.
But enough sarcasm.
The marine green algae Bryopsis are, to my perception, the most prevalent and problematic sort of ‘hair alga’ around our hobby, colonizing and dominating captive reefscapes with a speed and remorselessness that would make a Spanish conquistador blink.