My new aquarium has been up and running now for approx. 3 weeks and the fish seem quite happy. All eating and swimming as normal.

What I have noticed is that the features I've added to the tank have a brown colour covering the surface off them. I assume this is algae as in the posting by Elaine earlier.

Have completed a 40-50% water change last night and the water looks a bit clearer.

Is this algae harmful to the fish and is there any way to get rid of it without removing everything from the tank to clean it?

If it's not harmful, will it go away naturally?

Can take some readings from the tank tonight if you need any extra info.

TIA