Showy Shaggy Hair Weed

That does look a lot better for ID. Of course, I am not an algae expert!

Thanks, that was the inly one in my book but I think I found a better match on the internet, it is Ulothrix speciosa, called Showy Shaggy Hair Weed.

Yours looks a lot thinner and greener than Himantharia elongatta to me.. I think a green algae rather than a red algae (Himantharia elongatta is a red I think)