Sorry about the delay roho, I am usually quicker that this... I remember that thread about Minh using LS from the coast and there was some concern about poisons or contaminants...but he reported no problems with this. I tell you, nothing could set up a better control than to try this in a nano with its limited water column and inclusion of inverts! IMO I think it will be okay---you'll probably have much better sand biodiversity using real (oceanic) sand than just aged aquarium sand, just a thought. How long your tank will support this biodiversity will depend on a host of factors, but its nice to get the original seed FWIW.
Hopefully our PM will give you some insight in pinpointing the cause of red cyano outbreaks, was there any particular reason for the switch--aesthetics or functionality concerns? just curious. I am about to supplement my LS with some pink-colored crushed aragonite (layered on top) because I want to get an aggregated look to my sandbed (along with a few empty shells of various sizes) like Ghost of CHeese Sandwich's. His SB looks really nice, Im doing it more for looks as I don't think Ill get any added reduction characters from this change, its a way to do something new.
Brandon