Black Sand..

[ismvel]

Seed the sand bed with a newly cured piece of live rock or some black sand from someone else's tank and your sand will become live with time.

Thanks Ping....I knew this was the case with the sugar sized aragonite sand I used in my previous tank, but wasn't too sure about the black sand...

I have a 42 gallon that I was using as a sump, that I want to start up until I can get my 220 set up.....That way I at least have some rock and corals to put in the big one when I finally get a chance to get it running....

I want to try the black sand for the smaller tank with the 1" sand bed you suggested...then for the larger tank, I will use the regular sugar sized DSB, I was thinking between 5 - 6 inches.....I could then probably throw this black sand in the sump since it should be full of life by then...

Thank you all for the help.

[Ping]

If you put a DSB in a display tank the rock should be placed on the bottom before the sand is placed in.

If the 42 is only a temporary tank why go with the black sand at all. If you go with argonite based sand now, then you can use this same sand to seed your future DSB and not have a color differential. Just a thought.

[ismvel]

Thanks for the advice Ping, I have read that several times before (placement of rocks, then fill sand, avoid rockslides and other things)...I have been wanting to try the black sand is all...but you do make a valid point....when I get down to San Antonio and get settled in, I will decide whether or not to go with the moon sand or regular sugar sized aragonite.

[marcus_the_clownfish]

i was starting a new tank and wanting live sand to start off with, i was impatient and didn't want to wait for the black sand to become alive.

[tony]

ive heard it is very hard to keep clean

[Ping]

ive heard it is very hard to keep clean

That makes a lot of sense.

[SA-DSM]

I have it in my 72 bow and it really is not that hard to keep clean. But then again I have a good amount of snails to help with that.

I think Ace also uses it in his clam tank.

[dabudkrew]

any pics?

[matt]

Whether the black sand will support the kind of micro community that typical sugar size aragonite does will depend on the size of the grains and to some extent the texture. Apparently sand dwelling creatures require somewhat of a specific grain size; it just turns out the the sugar size particles will support a larger diversity of tiny critters than will smaller and larger grains. This info is all in Ron Shimek's book about sand beds. If you're going to have the sand bed, I'd recommend reading that book. It's short and cheap. (like me!)

Regarding the buffering, what happens is the sand, which is calcium cabonate, will very slowly dissolve, releasing calcium ions and cabonate ions into the water. The two primary ions in sea water that get used by corals and coralline algae are calcium and carbonate, so you need to constantly replenish them.

The problem is that the rate of dissolution is dependent on ph. That's why people use calcium reactors, which basically pump CO2 into a tube of circulating water filled with calcium carbonate. The CO2 lowers the ph until it's about 100 times more acidic than tank water, which speeds up the dissolution, then you drip that acidic water which now contains a very high concentration of calcium and carbonate into your tank. At normal tank ph (8.0-8.3) there is so little dissolution that the effect of releasing calcium and carbonate is negligible. Some people have argued that deep in a sand bed the ph does drop, but it doesn't drop that much, and since there is almost no circulation, if there were areas that contained water "enriched" with dissloved calcium and carbonate it would not circulate into your water column enough to make any sort of difference. If there was enough circulation to bring the water out of the sand bed at any sort of practical rate for buffering, that circulation would raise the ph because the water has O2 in it. Make sense? Ph in tank water is always directly the result of CO2 vs O2 amounts in the water, assuming there's enough carbonate present.

Now, if you want to have a deep sand bed for other benefits, like denitrification, that's great. I like the way they look, too. I disagree about putting the rock on the tank bottom and buliding the bed around it, though. Deep sand beds need a good amount of area to work well, and if you put the rock down to the bottom of the tank, you might be taking up more than half of the tank floor. Personally, I just put the rocks on the sand, pushing them in a little, but other people have made nice PVC stands for their rock and it works really well, supporting the rock in a nice sturdy way and allowing the sand to cover the whole tank floor, as well as increasing water circulation around the base of the rocks.