dsb question / miricle mud question

bolton reefer 1

New member
im tackling a high nitrate problem my sand bed was about 2" i beleive under 3" has no benificial effect so today iv removed all of it now instead of throwing it i cleaned it through and placed it in the sump on top of the 3" of miricle mud thats about 6" altogether will this creat a none oxygen layer to help remove nitrates or should i have binned it has anyone anything to say about miricle mud.