What is the brown stuff on the glass an powerheads in my saltwater fish tank??

Question

I have been seeing some brown spots all over the front of my tank and on the powerhead, also on the part of where the water flows into the tank from the filter. It is the color of rust. what is it???

Answer 1

depends on how long your tank has been set up. could be diatoms. maybe some algae?  If your tank is still cycling, this is normal, dont be alarmed. you will see algae blooms.  

Answer 2

could be mineral deposits, do you have hard water where you live?

Answer 3

touch it. if its slimy its brown algae, if not i have noo idea what it is. sorry=/

Answer 4

bacteria

Answer 5

Likely brown or red algae, brown is seaweed and a sign of a healthy tank, red is lack of oxygen and not healthy. Due to the placement I'd go with brown, get some good snails to take care of it for you.

Answer 6

it is just dirt get a catfish