Which kind?

Question

What is the best substrate (grevel, sand) for a marine aquarium, and the cheapest.

Answer 1

"Gravel" and "sand" can mean a lot of things - from size to material they are composed of. The best choice for a marine tank is something made from aragonite. This includes material that is crushed coral, small shells, or a form called oolitic (small, perfectly round grains). Aragonite will help maintain the proper pH in your tank. If your tap water has a high pH, this is not so important, but if it's low (like mine) it helps keep the water chemistry where it should be. Regular sand (play sand) won't do the same thing because it's made from silica. Silica can lead to overgrowths of diatoms which use the silica to make their outer "shell". Regular aquarium gravel is also silica (if natural color). While the gravel & sand may not be bad and still give beneficial bacterial a place to grow, it doesn't do all that an aragonite substrate can.

Another consideration is what fish you are keeping. Wrasses, gobies, and others will need to burrow in the substrate, so it's best to go with something small-medium sized. If you're keeping a puffer or parrotfish, go large so they can trim their beaks with it.

Answer 2

Aging ... is right on.
Sand is the way to go for a Marine environment. Don't skimp by buying "playground sand" buy good quality and wash it and soak it well. Expect a few days for it to settle (cloudy water) before being right.

Answer 3

hey dude, if you wanted cheap, you shouldn't have gone with marine tanks! haha.
But anyways, sand is the preference among all the marine enthusiasts i've talked to over the years. just make sure you let the tank filter for, like, three days or something before you add anything besides live rock.

Answer 4

buy sand from the pet store. don't just buy sand. it will turn into goopy clay/cement uck that will permanently cloud the water until you clean it all out and start over again with sand made for marine aquariums. cheap and marine don't mix.