Mixing different size sands

[ddm_aet]

My 75 gallon tank currently has about 2" of sand about a size or two up from sugar size sand.

I want to add more sand to get a total depth of 3 to 4 inches.
Can i add sugar size sand to this, or is it a bad thing to mix diffenent sizes together.

Overtime the smaller particles will settle to the bottom i guess..

 

[roka64]

Overtime the smaller particles will settle to the bottom i guess..

True, I used to have CC/LS, the coral shifted to the bottom.

Can i add sugar size sand to this, or is it a bad thing to mix diffenent sizes together.

Only issue I see here is future clean up crew/fish. I'm not sure of all of them, but some critters like smaller grains and others don't mind at all.

Some one w/more sand/critter/fish experience might be able to give more input.