The really red stuff Tropica sells (and probably is a variation of it) is a bit trickier, but plain old Ludwigia palustris of the kind you see in ditches and ponds all over the place is totally easy, even in low tech. You don't see people trading it much. But depending on where you are, you might be able to find some yourself.I see a variety of claims for the light needs of Ludwigia Palustris. Some sources say it's a low light plant, others say it's medium light. Is anyone keeping it successfully in low light? Especially in low tech?