DSB aka deep sand bed

[mpishi]

i've never seen this addressed but i have a dsb in my 33 gallon tank that is about 5 inches level deep ( or at least it used to be )

but the burrowing, digging, landscaping of brittlestars, crabs and shrimp create hillocks, hummocks and trenches almost down to the tank bottom in some places with sand piled higher correspondingly

any suggestions as to how this would affect the effectiveness of a deep sand bed

tia