Originally Posted by
soulsigma
http:///forum/post/3000550
Please inform me on the difference between the following substrates
1) Crushed Coral (why it is not wise to use?)
there has been much discussion over the larger size of substrate such as cc collecting detrius but not providing the same types of bacteria/invertabrates etc.... to break it down which results in higher levels of nitrates. can be large argonite or as the name implies crushed coral skeletons/rock
2) Aragonite
Argonite sand disolves at a ph less then aquarium water usually which is beneficial because over time it can release some calcium and carbonate alkalinity.
3) Oolite
is a size of argonite sand oolitic sand is usually collected in the bahamas. Alot of people buy this sand because it is very white. This helps with corals because light is reflected up off of it. Another tought is that it is so fine grained that detrius is not able to penetrate the surface keeping all waste on top and then circulated back in the water column to be removed by filters. This may be true at first but like any other substrate it will eventually become dirty andwaste will get into it. no big deal because bacteria invertebrates live in sand to break waste down. also depending on ammount of flow this sand can easily be blown around aquarium.
4) Reef Sand
not sure what reef sand pertains to uless it is just labled on the package. It is still calcium carbonate base but may not slowly break down in aquarium because unlike argonite other calcium carbonates break down at a much lower ph.
personally i like an argonite sand that is usually a size #1 (oolite being #0) some people even mix oolite and a larger size which can be ok to make sand slightly more bright but i would go with more #1 over#0.
this is just my preference though.