Can’t open video on my phone but hair slgae will be green and hairy whereas bryopsis which is similar will have fern like foliage/strands and also visible roots
For either, pull as much as you can by hand and then reduce white light intensity or time that white lights are on
For hair, add snails such as astrea, turbo grazer, nerite, cerith and a dozen carribean blue leg hermits
For bryopsis, take rock out and remove roots with a dental pick or small crochet needle and return to tank, then add snails such as astrea, trochus, ninja star, chiton and a pencil urchin
lights reduced or off period is 5-7 days
Forget chemicals which are often alternative and not long term solutions