"StringerBell" wrote in message ...
I already have a 3-4 inch sand bed in my aquarium. I was wondering if I
could safely add another inch into the already established tank (6 months).
I`m thinking of Arag-alive Fiji Pink.

You could, but I would not do it all at once.
You do not want to cover the current alive surface layer
of sand with too thick layer, blocking the oxygen under...
If you add in small portions spread thin you will let
all animals crawl up and populate this new top layer.