Coral Reef Forum

Looks like hair thats reddish brown on live sand and/or rocks.  If you have an already established tank and are haveing this problem this is what I did to rid the tank of the algae:

To get rid of it, your going to have to pluck it out by hand. Your going to need a bucket (to place the algae you remove) and a jar of fresh water. Daily you have to remove the algae by hand and put it in the bucket. Then rinse your hand in the jar of fresh water to remove any algae particles that may be on your hand and repeat.  If it takes a while I'd dump out the fresh water in the jar and replenish it with new fresh water, so you minimize the transfer of algae particles back into your tank.

Also, increase the flow to the area where the algae is growing.  Have a powerhead push more water through that area to inhibit the growth of algae.