Is sand* an OK/Good substrate to use with Bumblebee gobys and Figure Eight puffers?

If not I'm open suggestions...

Stu

* The stuff you buy from the bark/stone/landscape yards, well washed, pH neutral, which is the same stuff I'm using in my grow out tank

Sand's pretty good for the puffers because they like to make burrows to sleep in. I use sand for my BBGs and they're fine too, so I'd say yup. Maybe choose a sand that has buffering capabilities if you want a little help keeping your pH high and stable.

i keep my bb gobies in a tank with a mix of white sand and coral sand i have heard they like rocky areas but i guess if there is somewhere they can hide and call their own they will be happy

goby's and figure 8s together? I thought this wasnt such a good idea? Im currently setting up a 120litre tank and plan on getting a black ghost knife. Im looking to put something other random fish in it, would love puffers?

They both live in brackish water and F8s are quite placid for puffers. However, don't be surprised if you wake up to 1 less BBG one day. They can live together for ages then suddenly start eating their tankmates.