sand clumping?

[kennethstowell]

what causes your sand to clump? i have about a 2" sand bed(carib-sea) and ive noticed it clumping in diff. areas

[R334]

Do you drip kalk or suppliment calcium in any way?

[Randy Holmes-Farley]

Kenneth:

what causes your sand to clump? i have about a 2" sand bed(carib-sea) and ive noticed it clumping in diff. areas

There are at least two theories, neither of which have been proven.

1. That excessive supersaturation of calcium carbonate within the tank leads to precipitation of CaCO3 on the sand. As the growing crystals hit each other, they become connected, solidifying the sand. High pH, alkalinity, and calcium together lead to high supersaturation.

2. That bacterial action cements the grains together in some fashion, likely with organics between the sand grains.

Here's an article that addresses some of these possibilities:

http://www.animalnetwork.com/fish/library/articleview2.asp?Section=&RecordNo=181