if it can dry out, it will die. it will leave spores behind though, which produce new strands when you refill... so beware. you could always kill it with Flourish Excel, which kills it outright. BBA is a monster above hair algae in my opinion. that stuff likes to just grab and never let go. that or not grow no matter what... i cant get it to live in one of my tanks, no matter where i put it.