substrate granular size difference

[Cottaball]

What are the differences between using different granular sizes for buffering substrate. I currently use a medium size of 2.5mm size. I am thinking about trying the smaller granular which looks like powder. i realize there are big to small gravel sizes. 

 

to me, here are the pros of the powder size:

1. planting plants are easier

2.  baby shrimps cannot hide in gravel so don't get lost.

3. looks more neat as it fills out better. 

 

maybe con is more surface area so loses buffering sooner? 

 

 

 

[turok]

Last time I used powder it turned into one solid chunk of soil.  

You have to change powder more often.

If you want to use powder, put the powder into little pots, clear plastic, and try the powder out.