Tearing down 65 gallon tank red slime algae problem

[MaryA]

Thanks for having me in your group! I’ve been sick for a while and gave away my corals. I kept the live rock and damsels. I had actinic and metal halides and it looked nice. Now a wasteland of red algae and two triggerfish, and damsels. Transformer for lights blew, stand is starting to lean, time for a trade. Tank is about 20yrs and fish 5. How, after scrubbing, do I kill the slime algae and keep it from getting into a new tank? Your comments are appreciated. Yes, asking the lips to take triggerfish