Yes, like that. A couple of hours should be enough but it won't hurt to leave it another hour or two. When the rootball is hydrated put it back in the pot and then hold it to gauge how the weight feels, then you will know next time if it feels much lighter. You don't need to keep it as heavy all the time as it is when it comes out of the water but it gives you an idea of what is light and what is heavy.
