hear algae + browning corals

[naesco]

It looks to me that you have a water quality problem. What causes it may be lite skimming, late water changes and overfeeding and poor water coming it.

You can correct it by more dilegent more frequest water changes.
Consider investing in one sea slug to get the algae in control. Acclimatize it very slowly and give it a way when the algae is 90% done or you will starve it to death.
Nice tank pics BTW.