Rust like substance

Question
My saltwater tank has been up and running fine for about six months.  I have tons of water currents, an external sump system, and all of my tests have come back good.  My problem is that I have a brownish-orange coating starting to spot on my tank glass and it is on the surface of my rocks and sand.  This is causing my anemonies to become "unhappy". Any ideas as to what it may be, what may be causing it, and what possible remedies there are for me to experiment with?

Answer


David,

it sounds like this is an algae breakout.  Do you have a protein skimmmer or UV sterilizer for your set-up.  These two items really reduce the chance of nuisance algae occuring.  

Also if your nitrate and phosphate are a bit high.  This will lead to break outs.  When your anemonies are unhappy look at your lighting set-up ( I hope you have good metal halides/compact fluorescents for optimum health)
lights need to on for at least 12-14 hours.  Also these guys do not like increased nitrate/phosphate levels.  If the look a little deflated my bet would be lighting and slightly high nitrate (should be less than 15 ppm) levels do this all of the time.

lastly when brown/rust algea appears in established tanks it is a sign that light levels are too low or perhaps they have lost some of their intensity.  Increasing the light will cause this brown film to go away.

good luck
todd