Freshwater to saltwater question.

[jutter]

Hey guys, not sure if this is a stupid question but I got a freshwater tank second hand with sand in it. I want to turn it into a saltwater tank. There were no fish in it when it was with the previous owner. Do I have to take out the sand still?

[bribo12]

Yes I would replace it with an aragonite based sand. That old sand is probably littered with phosphates and will lead to nasty horrific algae outbreaks. Plus it won't buffer your water like aragonite sand will