# rocks



## truck_317 (Oct 9, 2008)

ok i hate buying larger rocks from a fish store becuase they are so expencise. i see alot of people with tanks that has rocks from out side. my question is what rocks are ok to use in my tanks and what rocks are not ok. and if i can find the ok rocks what i do have to do to them to make them safe. *** heard u have to boil them and such please help


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## mia_ann (Dec 20, 2008)

http://www.cichlid-forum.com/articles/rock_metals.php

I hope this helps and good luck


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## truck_317 (Oct 9, 2008)

so will limestone rock work or not my ph in around 7.8. also how can i tell if it is a limestone rock. most if the creeks around here i belive are limestone.


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## mia_ann (Dec 20, 2008)

In practice, the power of limestone rocks to significantly raise the pH in an aquarium appears to be rather limited. This can be attested by many African rift lake cichlid aquarists who have found that simply having limestone rocks in their tank will not buffer the water up to the levels they may desire.

I guess it depends. You could put it in there and do pH tests to monitor levels for a while. If it gets to high, just remove the rock and do water changes.


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## truck_317 (Oct 9, 2008)

how can i tell if it is a limestone rock


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## mia_ann (Dec 20, 2008)

I'm not sure. Maybe study some pictures of limestone online and compare to rocks you find? Someone else can probably help you more with that than I can.


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## venustus19 (Aug 30, 2007)

i bought my limestone rocks from a landscaping place... some places have like a junk pile... i picked up all the pieces in my tank now(about 8-10, ranging from about 15 lbs-35 lbs) all for $10... not sure how to tell if it is limestone for sure, but looks wise, it almost looks like concrete, color wise anyway... have a look at my link in signature, or my tanks and see... google limestone rocks too, should find plenty of info on it...

limestone does increase ph, so for me it was good, as i need about 8-8.2 for ph... after while, kinda lose the ph deal with the rocks, as i now add baking soda after water change to bring my ph back up...

HTH


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## newfisher (Dec 20, 2008)

Limestone is a sedimentary rock formed in ancient oceans usually, either as calcium carbonate precipitate depositing as "mud" on the bottom, or mixed with corals, or as an evaporite depositing in shallow marine environments. Limestone may also form in fresh-water environments (lakes), but it is often mixed with more silicate-based muds as well.

Due to its varied genesis, limestone can take on several forms ranging from mudstone, to fine crystalline, to coarse crystalline rock. It often contains fossils. It is usually medium gray (concrete color), but can vary from light to dark gray to almost black, and from tan to maroon. You should be able to scratch limestone without difficulty using a common nail.

The best way to test for limestone (assuming the rock fits the general descriptions above) is to put a drop of ~10% HCl (hydrochloric acid) on a sample of rosk. If it's limestone, it will fizz quite violently. If it is in the coarser crystalline form and fizzes only mildly, then chances are that it is dolomite ... limestone that has metamorphosed. Both are safe generally for aquariums, particularly where high pH is desired.

That said, look closely at the rock, break some samples from your source open to better examine it inside ... before putting it in your aquarium. Limestone can on rare occasions contain base metals that include copper, lead, zinc, and others. I know of at least one limestone- base metal mine that also produces limestone for landscaping and architectural purposes ... it is too low grade to process for mineral values, but it is good for the other functions and the quarrying equipment is at hand to produce it. Limestone found in the "wild" in creeks, etc. may also fall in this mineralized category ... better to be safe than sorry.

If you can't get your hands on hydrochloric acid for testing purposes, look for muriatic acid in hardware stores (it's used to clean concrete) ... it is HCl. It can be sold in different strengths. Check the concentration on the bottle and dilute if necessary to obtain a ~10% solution. If the concentration is less than 10%, then the reaction rate will decrease proportionately ... you will need to interpret results accordingly. Buy the smallest quantity of muriatic acid possible if your only need for it is to test limestone ... a pint of muriatic acid will be enough to do over 2000 tests!

Hope this helps?


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## a_c_arnold (Mar 7, 2008)

I usually just find a creek and pick out the ones that I like. Field stone usually works pretty well. It's good to avoid really soft rocks that may disolve into the tank water. Buying rocks at most pet shops is a complete rip off and their is nothing special about the rocks that they sell. Rocks from a hardware or landscaping store will work as well, and they usually have a lot bigger selection.


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## Mcdaphnia (Dec 16, 2003)

truck_317 said:


> ok i hate buying larger rocks from a fish store becuase they are so expencise. i see alot of people with tanks that has rocks from out side. my question is what rocks are ok to use in my tanks and what rocks are not ok. and if i can find the ok rocks what i do have to do to them to make them safe. I've heard u have to boil them and such please help


 There are lots of great looking rocks around the State College area. Used to visit often when my daughter and son-in-law lived there. Get persmission from the landowner and pick out what appeals to you. It should be hard, not soft like a shale or eroded sandstone. If you can get a powerwasher, you can skip the boiling. Clean completely and if you have a cutting tip, it's black on my son's, you can cut holes in the rocks.


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## truck_317 (Oct 9, 2008)

most of the streams around here are limestone i think. so i will have to check that out. also i could probley go up on the mountains and see what they have too


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