Coral Rock?

[This Old Spouse]

I was recently in Florida and picked up some beautiful coral rock from a beach. I'd love to put it in one of my tanks, but will it be safe? One tank I have houses crabs and guppies, another has guppies and cories.

 

[Proxo]

I was recently in Florida and picked up some beautiful coral rock from a beach. I'd love to put it in one of my tanks, but will it be safe? One tank I have houses crabs and guppies, another has guppies and cories.

Umm, i THINK it'll raise your pH? how much, i dont know lol.

 

[BigbruiserAl]

Try the fizz test? a drop of vinager, if fizz's stay away

 

[fluttermoth]

Don't put coral or coral rock in a freshwater tank..three reasons;

1; it will dissolve and be ruined
2; it will dissolve and raise your pH to unacceptable levels; probaby even for your guppies, let alone your cories!
3; it's too sharp; marine fish are used to navigating sharp obstacles and won't get scratched, freshwater fish aren't and will

Put it on your mantlepiece/shelf and enjoy it

 

[StandbySetting]

Guppy's have been found in marine environments, even those with a salinity of 150% of that of normal sea water so the PH will be about 8.2, and as for the crab what species is it? For Guppy's alone it should be fine, Coral Rock is Calcium Carbonate, and is used in marine tanks, it's highly porous so is a great place for bacteria to colonise, it will raise the PH to about 8.2, and increase the KH and GH also, it's just that when you do water changes the PH will fluctuate ever so slightly, unless you do small ones of about 10-20% in which case it will be negligible, the Guppy's will be fine with it, the crab however may not, if it's a Brackish species then yes it may be suitable, if it's a fresh water then no it wont be.

 

[fluttermoth]

Oh, well, I'll stand corrected on the pH then!

It will still dissolve away and be ruined though; I stand by that part

And I still think (even without having seen it) it would be potentially too sharp....

 

[StandbySetting]

The solubility of Calcium Carbonate is 0.00015mol/L, so only 0.015grams of CaCO[sub]3[/sub] will dissolve per Litre, it'll take a long time for the whole lot to dissolve, so a rock with a mass of 1Kg will need 66,667 Litres to dissolve it completely under standard conditions (25[sup]o[/sup]C).

The length of the tail will play a part in whether or not the rock may cause problems, short tailed individuals shouldn't have problems but those with long trailing tails will.

 

[This Old Spouse]

No cories in this tank, just female guppies and fiddler crabs. It's the crabs that have me inclined to use the coral. It's not very sharp, either. These were chunks that had washed up on shore, so the sharp edges were smoothed out.

However, I don't want to take ANY chances that this might hurt anybody.

 

[StandbySetting]

I presume your tank is a Brackish set up? Fiddler crabs are found in estuaries, they need access to land as well, ideally you'll want an SG of 1.005-1.010, the PH increase will be fine for both the Guppy's and Fiddler Crabs, the Brackish conditions will also be fine for the Guppy's.

 

[fluttermoth]

I just remember reading somwhere that freshwater fish shouldn't be kept with corals; it could well be wrong; it was a long time ago

I know it would take ages to dissolve altogether, but I remember in my early days of fishkeeping putting some precious (to me) sea shells in a tank and they'd changed significantly by the time I noticed and took them out, that's all I meant

 

[This Old Spouse]

I presume your tank is a Brackish set up? Fiddler crabs are found in estuaries, they need access to land as well, ideally you'll want an SG of 1.005-1.010, the PH increase will be fine for both the Guppy's and Fiddler Crabs, the Brackish conditions will also be fine for the Guppy's.

It is indeed a brackish setup. It's a 3/4 full 10g with mostly gravel but some sand, and two large rocks that the crabs can climb and get completely out of the water.

I just remember reading somwhere that freshwater fish shouldn't be kept with corals; it could well be wrong; it was a long time ago

I know it would take ages to dissolve altogether, but I remember in my early days of fishkeeping putting some precious (to me) sea shells in a tank and they'd changed significantly by the time I noticed and took them out, that's all I meant

I appreciate your comments! I had no idea what putting them in there would do, and that's why I asked, to get as many opinions as possible.

These rocks aren't precious to me. Just kind of cool.

 

[StandbySetting]

They'd be fine to place in the tank, my guess is that the PH is near 8.2 anyway due to the salt, adding this wouldn't do much at all from a chemistry point of view.

 

[This Old Spouse]

Okay ... I'll do some rearranging with the next water change tomorrow!