Bubbles from sand and crabs

[citytee]

Ok, crazy question, I have small bubbles coming from my sand and it looks like some from my hermit crabs, any body have any idea what would cause this, do the crabs have gas LOL, any ideas????

 

[zesty]

pictures??

How old is the tank? What are the magical numbers?

Any more detail?

 

[citytee]

The tank is only a little over a month old, heres a time line:

Started Tank fill on 11/8/2014
Added Live Rock 25lbs 11/8/2014
Added Live Sand 80 lbs 11/8/2014
Tank filled on 11/12/2014
Added Shrimp on11/21/2014 @ 12.30pm
Added 10lbs Live Rock 12/4/2014
Added 15lbs Dry Rock 12/4/2014
Added Hurmit crabs 12/5/2014
Added Nerite, Cerith, Nassarius Snails 12/5/2014
Added Cheato12/5/2014
Added Fern Caulerpa12/5/2014
Added Blue Damsel 12/13/2014
Added LED Light (Current Ramp Time Pro) 12/17/2014

Here they are as of last night:

Date	Time	PH	Ammonia	Nitrite	Nitrate	Temp	Spacific Gravity
12/21/2014	7:20pm	7.68	0ppm	0ppm	10.ppm	79°f	1.024

The bubbles were starting to be noticed two days ago and they don't seem to do it all day.

 

[citytee]

here's a picture

 

[citytee]

Bump