Red spot on rock and sand

[Ra7deepan]

My saltwater Aquarium tank is 68 days old.. Now I see some red spots on the rock and sand bed. May i know what is this?

 

[MnFish1]

It could be a red-algae - or cyanobacteria. Is it firmly attached to the rock - or easy to blow off. Does it come and go - i.e. less in the morning, more at night after the lights have been on during the day?

 

[TheMetalReefs]

looks like cyanno to me. just do nothing. maybe try syphoning out doing waterchange and blow it off with a turkey baster and catch it with some fleece or filter sock, but it will eventually dissapear omce the tank stabalizes a bit.