Varied Depth DSB?

[benihuma]

I have a 90 gallon tank with a DSB that is 4 inches deep for the front half of the tank, and then tapers down to about 2 inches in the back. Is this OK or should I add more to the back? The reason it's not even is due to my fish swimming in and out of the rock in the back of the tank moving sand towards the front.
Ben

 

[mr . salty]

This should be fine.I also have a few shallow spots in my tank due to an overactive clownfish.He doesn't like deep sand around any of his three anemones and constantly digs out around them....