DSB question

[Aquattro]

I've used mildly deep sand beds over the years, no issue. But my last tank, set up pretty much the same as the ones previous to it, had the sand solidify in about 4 months. I mean solid. I took the 24x48 inch sandbed out in about 7 pieces...I never figured it out. I have 2 inches of the same sand in my current tank, no issues in 18 months...

[monocus]

possibly calcium is gluing it together

[Myka]

A spike in alkalinity will cause sand to bind like that. A spike you may or may not have known about.

[marie]

Take a small clump of the sand out and put into a container of bleach and water. If the clump breaks up into the original sand particles then it is bacteria or algae holding it together. If it stays in the original clump then you have calcium precipitating out for some reason

[daplatapus]

Originally Posted by marie

Take a small clump of the sand out and put into a container of bleach and water. If the clump breaks up into the original sand particles then it is bacteria or algae holding it together. If it stays in the original clump then you have calcium precipitating out for some reason

Hmmm, cool, I'll try that.
Thanks for all the responses so far.