Deep sand bed

[marie]

I like sandbeds just for the extra critters it provides home for. I believe our tanks, just like any ecosystem should be built on the pyramid system.....large numbers of algae/bacteria, smaller numbers of critters that eat the algae/bacteria and fewer yet critters that eat them. Not easy to do when you have limited space and want to have things that you can see

[Jpeter]

I just set up a 36 gallon tank with 2 inches of sand and after learning how a DSB works I want to add two more inches.
I set the tank up 4 days ago can i add two more inches or should i just add one and wait a week then the other inch.