Originally Posted by grubsnaek
does that look in the safe zone
I would go with the 2 inch. Couple of reasons.
DSB will look nasty on the front of the tank and you will be inclined to clean and stir it up. Bad.
If you do get a "gas pocket" crash, you will have to deal with it then, when you have frags all over the place. After the fact removal sucks.
If you have a crash or your parameters get out of whack, you will forever wonder if it is the DSB. With a good water change on a 2 " bed, you can correct water issues quickly. With a DSB problem, you can't.
A DSB will crash about 50% of the time at some point. It will smoke your tank.
Hope this helps. Go for 2!
Mike