Rust covering rocks

[jassz]

Hello experts,

More newbie questions. I have had my tank 6 days (moved an exisiting set up). For several days now the rocks and equipment has been getting more and more rust coloured. At first I thought maybe it was coming from a rusty sump, and that rust blew out from a couple time when the sump accidentally sucked up air. I tried scraping a bit off with a some tongs and it doesn't budge so I don't think it a dusting of rust. I googled this, and it sounds like it might be algae. What do you think? What should I do about it? I have a predator tank, with 2 triggers, 2 puffers, a wolf eel, a lion fish, 2 tiger cowrie snails and a handful of hermit crabs.

The water is also quite cloudy. I am getting a protein skimmer tomorrow (it doesn't currently have one). Will that help?

Thanks,
jassz