Than it is not a deep sand bed.. Just a sand bed.
It will not have the benedit of anaerobic bacteria at the bottom. There is no rule on how deep just that if it is too shallow, 02 will get to the bottom negating the DSB.
Thanks Wamp and BigMac! I think I'll add at least another inch of argonite (slowly) just to be on the safe side!!!! Esp. because I have a lot of circulation and some spots are deeper than others....
