Limestone sand

[waterbury guy]

I want to change my CC and UGF to a DSB. My tank has just begun to cycle with (4) damsels. I have found some sand at Home Depot labeled play sand and made from limestone. Any thoughts on whether this is good or bad? Also I have (2) 201 Powerheads with a Penguin 400. Right now I have airation coming up two of the tubes in the UGF, if I take out the UGF what do I do for airation? I am going to be FO for a while, then introduce inverts and corals in a few months. Thanks for any help.

 

[kris walker]

Limestone is the same as calcite and arragonite (CaCO3). Yes, you can use that sand for a substrate, and in fact, most people would love to get their hands on some of it. What you are most likely referring to is "Southdown" sand, which is composed of arragonite (arragonite is a more soluble form of limestone than calcite).
Congrats on finding Southdown, and welcome aboard!
sam

 

[thewolfman777]

i have a few bubble strips in my tank. i feel it is not only good for gas exchange but adds a nice look to the tank. Do you need air stones, no, because your other filtration usually takes care of the gas exchange (surface agitation). it is important for the surface of the water to be agitated, so whichever way you feel the need to do this, i feel the job is being done.

 

[waterbury guy]

Just a FYI on the limestone sand I found. The HD in my area (Vermont) doesn't carry the Southdown sand until Late May. The stuff they do have on hand is by American Sone Mix, called Amstone Play Sand. Thier SKU# 350-983 it's like $5 for 50 Lbs.

 

[kris walker]

Oh, then it may not be arragonite. You should check, as if it is calcite, it is no different then crushed coral you would get at an lfs. However, if you want a cheap substitute to cc, then by all means.
EDIT: to tell the difference between the two, arragonite sometimes forms "oolitic" forms where each sand grain is very very rounded. It would break more easily than calcite as well. Arragonite is not always oolitic, but if it is, you know it is arragonite.
sam

 

[fshhub]

do not airate, it is not needed, only surface agitation, you can get this by aiming a powerhead at the surface, but you do not need or want to use an airstone
HTH