Rock found on beach

[jsanchez]

My girlfriends parents went to Florida about 12 years ago and found a nice softball size rock washed up on the shore, looks to me to be mostly the skeletons of corals. They've now had it in their backyard exposed to the elements for that duration. How can I go about cleaning the rock and making sure its safe to use for my tank? Searches online haven't really helped much.

The rock looks nice but has a green coating? It's not a slimy coat but looks stained a shade of green. Im sure they're some bugs living in it as well.

 

[thedasher]

I've heard of people bleaching their rock then Having it sun dry for about a week then wash it off again.

 

[invertinoob]

muriatic acid bath for dead rock+google...

 

[racoloish]

You can use vinegar is more safe than bleach. Then watch it with water. I think (not sure) you don't have to wait.

 

[jsanchez]

Thanks invert for the positive agrees I've reply. Muriatic acid isn't something I'm comfortable working with. Maybe my Google searching skills are lacking but I didn't find the results to useful.

 

[Squid]

Google vinegar bath

 

[jsanchez]

Doesn't vinegar dissolve the live rock? I ask because I had tried cleaning some shells for my hermits with vinegar, perhaps used to much, and it ate right though the shell.

 

[NanaReefer]

Vinegar will dissolve anything calcium but not rock So if you think it's a coral skeleton do not use vinegar. Bleaching it is the safest method. Very little is needed, 1 part bleach to 10 parts water, rinse well and let air dry for several days. If you can still smell the bleach, rinse again and let dry.

 

[jsanchez]

I'll give it a try. After doing some research I found that the vinegar, or muriatic acid, will dissolve the very top layer of the rocks. This apparently will help remove the majority of impurities and any bonded nitrate and phosphate.
Any idea as to how long I should soak the rock in vinegar? I'll be using a 50/50 vinegar/water mix.