Using Black Sand

I'd like to ask about black sand. Correct me if I'm wrong, but the black sand is not calcium-based, it's volcanic rock.

So is it a problem if you don't have the buffering capacity of the calcium sands?

Is it still useful for a DSB?

And is it sharp-edged instead of round-edged? i.e. is it a problem for digging critters or fish like a jawfish?

I really like the way it looks, but I won't use it if it's harmful........

You don't really need calcium sand for buffering, your live rock and alkalinity will do that just fine. It will work for a deep sand bed, but it is sharper for sensitive skinned animals. However, many beaches in Hawaii are black sand or have black sand mixed in and they still have burrowing critters, so it can't be that bad. Anything light colored will show up though like pet hair on black pants.

Its a myth that calcium sand will buffer your tank so in other words the black sand will be fine in your system.

One thing to keep in mind is the black sand can have all types of metals in it. Depending on what metals may be in it it may or may not be a problem.

Black sand also wont reflect light back up to the underside of your corals.

Oh yeah, forgot about the light difference, white sand gives better coral growth because of the extra light, of course you can compensate with more powerful lights...

The one time i ever used the black sand, pieces of it would always attract and stick to my magfloat... def metal in it, what a pia!

As mentioned, the whole idea of our sand beds acting as a buffer, is a myth. Well, not exactly. Our sand will dissolve, buffering our water, IF our pH drops to a low enough level. However, most everything in your tank will be dead, before that happens, as the pH level is about 6ish.

Black sand is higher in silicates and metals, which can cause phosphate and nitrate problems, much worse than aragonite based sands.

Volcanic sand shouldn't be magnetic. There are other "sands" made of various things like industrial byproducts which I would not put in a tank, but the stuff taken from the beach should be ok. I think Caribsea makes a good black sand, it's definitely volcanic because it has little green olivine crystals in it which indicates lava rock.

wow...........don't know HOW I missed this thread .......wish I got here sooner........I've ALWAYS loved the look of black sand but had many of the same concerns you have seawitch....interesting about the light reflections - and it makes sense......that alone might dissuade me from using it - - but it DOES look so pretty .......I guess it's like any sand though, you really have to know all that's in it before using it.................so what did you decide? if you're using black sand, have you noticed any cons? and got any pics we can see?

..................I'm still curious about hearing some pros and cons and who's brand is best, so........anyone here have some experience they can share with us?