Black sand

Just yesterday, i bought some more live rock and rearranged my aquascapeing, when moving the bottom one's a few of them had greyish sand under them, what causees this and will it do any harm?

Cheers...

 

Hi Stingray

I think what you are seeing is decaying fish, snail and crab waste that has been broken down by bacterial action and as its fine its being carried under the rocks by the flow in your tank


Steve

 

I suspect so as well. I moved to black sand about 4 months ago, and it's definitely lost it's glimmer. I have green stuff, that I'm pretty sure is algae (mostly) growing on it. It's also hard to vacuum since it's so light too.

 

That's the anaerobic area. Very little oxgyen is available under the rock so anaerobic bactieria grow there. It is normal and does not hurt anything as long as you do not disturb much of it. It will release toxins if you stir it up too much.

Jack

 

Thank you, this is what i suspected, i did stir it a little to even out the ditches, before replaceing the rock, but the patch was only around 3 inch square, hopefully it will be ok, cheers karma all round...