Sand and Vinegar Test

[fish1219]

Hello,
From reading multiple threads on this forum I understand that sand is suppose to fizz when vinegar is added if the sand is aragamax (aragonite) based. Has anyone done this test on CaribSea? I'm trying to understand the vinegar test. Will it desolve all of the sand or just fizz and leave some sand behind. I have an old bag of Old Castle Sand I found in my shed. When I add vinegar it does fizz but does not completely disolve.

[Travis L. Stevens]

Over time and with enough vinegar, aragonite will fizz and dissolve to a point of saturation. What is left over is not aragonite. Even regular play sand will fizz slightly, but pure aragonite is drastically different.

[Swanwillow]

but- it doesn't really matter, cause a fish tank doesn't have enough acid or base in it to disolve massive amounts of sand over time...

blah

[Travis L. Stevens]

<a href=showthread.php?s=&postid=6847341#post6847341 target=_blank>Originally posted</a> by Swanwillow
but- it doesn't really matter, cause a fish tank doesn't have enough acid or base in it to disolve massive amounts of sand over time...

blah

Nope, but if your pH drops low enough it helps buffer it to keep it from dropping too low. Also, over time, it does dissolve and realease Calcium back into the system.

[Swanwillow]

but, if the ph drops that low, your going to be losing fish and corals...

that low would be below 7.0, probably in the 5 range of the ph scale...

you'd loose fish at what, 7.5? depending on how fragile they were.

or going up, it would dissolve around 10... and fish would be affected at 9

[Travis L. Stevens]

<a href=showthread.php?s=&postid=6847502#post6847502 target=_blank>Originally posted</a> by Swanwillow
but, if the ph drops that low, your going to be losing fish and corals...

that low would be below 7.0, probably in the 5 range of the ph scale...

you'd loose fish at what, 7.5? depending on how fragile they were.

or going up, it would dissolve around 10... and fish would be affected at 9

Not necessarily. pH can drop in aquariums with high amounts of carbon dioxide in the system. It isn't uncommon for Calcium Reactor users to see pH steadily at 7.8 and have perfectly healthy and balanced tanks. I'm sure if it dropped down just slightly that you won't necessarily loose any fish over it. Albiet, it might be comprimising their safety and health. Also, many fish are able to tolerate a wide range of pH issues. Heck, the common Sailfin Molly is originally a brackish water fish and is found in freshwater of varying alkalinities all the way to full blown saltwater in the wild. But this isn't a thread on tolerance of fish but how aragonite dissolves.

The answer to fish1219's question(s) is in my first post (second post of the thread). The vinegar's pH is low enough (pH of 4) to dissolve the aragonite (Calcium Carbonate; CaCO3). Anything left over is not Calcium Carbonate. You just have to make sure you have enough vinegar for the the Calcium Carbonate to dissolve into before it reaches the saturation point.

To answer why Aragonite (CaCO3) is beneficial in the home aquarium is because you don't need that low of a pH to dissolve CaCO3. Albiet, it will only dissolve slowly and is dependant on atmospheric CO2. It will even dissolve in water (7.0 pH) fairly quickly. So, if something goes aury in your tank and your pH begins to drop because of an alk/ca imbalance, the aragonite will dissolve and keep it from dropping too quickly. Granted, CaCO3 sitting in the bottom of your tank isn't a prevent-all, it is an unseen helping hand to keep it under control while you fix the problem.

You can read more information here - http://www.advancedaquarist.com/issues/july2002/chem.htm