Help !!!!!!

[Sam1969]

OK .. so I am new and this may be completly normal and I may be a complete idiot so bear with me ..

I have just started my tank and has been running with 80 lbs of LS and so far only 11 lbs of LR for about 2 weeks now, all of a sudden when I get home from work tonight there is an infestation of rusty brown algae or somthing throughout my tank .. on my LS LR the top of my overflow and my return lines. Is this normal ? What should I do ?

dont know what my PH levels are as I dont have a test kit yet but my saline is 1.023 and the temp is 72