Live Rock Shrinking?

[TKEON230]

I just recently restarted my FOWLR tank that currently has a few snails, hermit crabs, and a mithrax crab in it. Over the past couple days I swear that my live rock is shrinking or developing "tunnels" in it. Is there anything that can eat through live rock? I didn't think that was possible. I've had this rock for about 2 years now.

 

[dskidmore]

Sure, all kinds of critters will burrough in live rock. I'd expect more tunnels than ouside shrinkage, you'd notice if some critter was scraping off your coraline.

 

[TKEON230]

Do you think the creatures are smart enough to realize when they've gone to far? I'm worried that someday I'm going to wake up with 40 gallons of water on the floor because some creature ate through rock enough for it to fall apart and shatter the glass.

 

[roka64]

I am not aware of any critters that use rock as their diet. Most will burrow and use that as their home.

 

[dskidmore]

I'm worried that someday I'm going to wake up with 40 gallons of water on the floor because some creature ate through rock enough for it to fall apart and shatter the glass.

Rock piles do occasionally fall, but I've never heard that quoted as a reason.

If you ever do a rebuild you could:

• Put plastic lighting grid or starboard on the bottom, so the force of falling rocks is distributed before it hits the glass.
• Epoxy your rock stack in place.
• Drill holes and peg your rock stack in place.

Overall, I don't think it's a concern really. Unless the critters digging these homes out are multiplying rapidly in your tank.

 

[roka64]

Good points!
I make sure my bottom layer of rock is resting directly on the bottom of the tank.

 

[TKEON230]

I do have my base live rock directly on the ground, I was more worried about the upper tiers falling. The "tunneling" appears to have slowed down a bit. I think it might be some of my hermit crabs because I have discovered them poking around near the newly formed holes.

You can see some of the holes I'm talking about above. There is some sort of feather duster worm thingy in one of the holes, but hermit crabs are hanging out near the other holes like right here:

 

[dskidmore]

The hermit crabs may be trying to eat whatever made the holes.