Sand Grain Size?

[FishyReef]

Getting ready to buy sand for my tank (finally), and have no idea what size grain to get. I know I need to get fine grained sand, but how fine? Petco has some that is somewhere between sugar sized and powdery (I'm guessing that is too fine), but the next size up seems to large to me. I do plan on having a pink spotted watchman goby in my tank, so need something that will be okay for this guy. LA says they need enough sand to bury in but that it should also have loose rubble in it. I'm not exactly sure what they mean by this, since I know not to go the crushed coral route. Do you guys just typically mix a few different sizes together?

Thanks!

 

[kbuser92]

A fine aragonite should be good.

 

[Waddi]

+1 Buser
I have a fine aragonite, my watchman goby is fine with it, sifting for days! :p