Dendrobium with Algae and Brown Leaves

[freezedried74]

I think the two issues are unrelated. I bought 3 clearanced Dens about a month ago. Since then I have repotted them in S/H and the roots are doing awesome. I can see new, vibrant green roots. Since I repotted, some of the leaves are turning brown. The canes still feel healthy. I hope my Dens are just adjusting to the new conditions. I also have algae growth in the S/H pot. I think I read this is normal. Is there any way to get rid of it? If there is, should I get rid of it?

Thank you
Brian