algea/nitrate culprit

[mookie]

could these rocks that were used in my old freshwater setup be causing my algae and nitrate.
i have a 50g with about 70lbs of live rock and about 30 pounds of this base rock
29g sump with chatoe
CSS 65

http://s153.photobucket.com/albums/s218/o0jmadr0x0o/?action=view&current=100_1624.jpg

i use RO water and do 5-10g water changes a week, but have been doing them more since i got my RO unit, trying to get algae and nitrates to go away

could it be these rocks?

 

[mookie]

BTW the tank is 7 months old

http://s153.photobucket.com/albums/s218/o0jmadr0x0o/?action=view&current=100_1605.jpg

 

[Subliminal]

I don't know about the answer to your question, necessarily, but I noticed from the picture you have only 1 powerhead in your display tank..?

More water movement sometimes helps with algae....helped with my hair algae problem, that's for sure...

 

[Carlo]

could these rocks that were used in my old freshwater setup be causing my algae and nitrate.

If you want to find out pull a rock or two and put it in freshly made up salt water. Test the ammonia, nitrites, nitrates & phosphates of this water before you put the rocks in it (should be zero) and let them soak for a couple of days to a week and re-test the water. If any of these 4 rise (aren't zero) then you have your answer.

It could be there was some type of life on the rock which is dying off kicking off a small nitrate cycle OR it could be there was built up phosphates in the rock that are now leaching back into your tank.

Carlo