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stones that will leach minerals into the water?

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what are some stones that will leach ninerals into the water over time?

i know baise rock will leach calcium
and granite will leach some minerals

what else would do the same
what about rock dust?
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Most basically:
Any rock that is limestone, calcite, dolomite or related will leach mostly calcium and magnesium carbonates. Many rocks are in this group with lots of names. Some are harder than others, so leach more slowly. Others are so soft you can practically see them melting in the tank, especially if the water is kept on the acidic side.

Most harder rocks like quartz, granite, basalt and lava tend not to release minerals. However, sometimes these rocks can have veins of softer minerals in them. Then the veins might dissolve over time, but the main rock does not.

The easiest way to tell if a particular rock will leach minerals under your conditions will be to test.
Set up a jar of water with tap water or whatever water you will be using in the tank.
Add whatever additives you will be using in the tank.
Test this blend to get a base level. What is the water like before you add anything.
Then add rock samples. The finer they are broken up, the more surface area, the faster you will see results. If you have to break up the rocks wear eye protection! Rocks can chip and fly when you hit them with a hammer.

Test for all the aquarium tests that are available such as:
TDS: Total Dissolved Solids will let you know SOMETHING is in the water, but won't tell you what it is.
GH: Tests Calcium and Magnesium.
KH: Tests carbonate and bicarbonate.
pH: is not actually testing minerals, but might change to let you know something is going on.
Other tests based on what kind of rock you think it is: Iron, Phosphorus, Calcium, and whatever other tests you see.
There are some good web sites that can help you find out what the local rocks are in the hills near you, and can help you ID rocks from elsewhere. You could try posting pictures here, too. Explain where you found the rock.
 

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Granite really shouldn't be leaching anything...

And any rock that will leach/dissolve, will do so quicker if there is more surface area.

A 1 lb chunk of limestone will dissolve a bit, 1 lb of limestone gravel will do so quicker, and 1 lb of limestone dust/flour will do so even quicker yet..

In addition to what Diana posted, you want to avoid anything that is a heavy metal ore, or an evaporite (gypsum, etc.), but these are a tiny minority of the rocks you will likely run across. Most rocks are going to be fairly boring old silicates.
 

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Sorry, but I need to hijack this thread. Has anyone ever seen this kind of rocks before? Know what they are? Know if they're safe?

 

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Smeagol, Are your rocks super hard, or are they flakey and leave sparkly specks on your hands when handling them? They are definitely metamorphic rocks based on the foliation (parallel alignment of mineral layers or banding of different colored minerals). If the rocks are super hard, they're most likely "gneiss". If the rocks are more soft, flakey, & leave sparkly specks on your hands, I agree with jrh and would say the rocks are a "mica schist".
 

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Smeagol, Are your rocks super hard, or are they flakey and leave sparkly specks on your hands when handling them? They are definitely metamorphic rocks based on the foliation (parallel alignment of mineral layers or banding of different colored minerals). If the rocks are super hard, they're most likely "gneiss". If the rocks are more soft, flakey, & leave sparkly specks on your hands, I agree with jrh and would say the rocks are a "mica schist".
Yep, they are definitely flakey and leave sparkly specks all over the place. Mica schist it is! Thanks for helping me id these rocks! So then, is mica schist safe to put in the tank?
 

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I think it should be fine. Most metamorphic rocks are inert (marble being the common/glaring exception).

Might want to wait till jrh or Ebeth check back in, as they both seem to be a bit more reliable geology-wise then I am.
 

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No, you're better than I am, Lochaber.

I can't think of anything that might be in there that you'd want to avoid, unless maybe it contains pyrites. I don't see any problem with the softness of the stone, because I agree with Locaber in that it's probably inert.

Personally, I'm waiting for Ebeth to chime in. :)
 

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Smeagol, I, personally, wouldn't put them in my tank. Schist is very prone to mechanical weathering, meaning the water will get in between the soft foliation groves and likely split them apart over a short amount of time. Mica schists are weird: micas aren't exactly clay minerals, but they can act like them. They'll get all over your tank, some clays are "swelling clays", etc., and will definitely cloud your water. Not to mention the possibility of metallic minerals in the schist, such as pyrite (shout out to jrh), blah, blah, blah. If it gets all over your hands just by touching, imagine what it will do to your tank. Sorry, I could go on & on & on. I'm sure you figured out I'm a geologist (who talks way too much). DON'T put them in your tank! Happy planting! Ebeth
 

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I got some. Me abd happi are doing a test to get exact ppm's of calcium and magnesium over a week in r/o. We will have results on a few days. The point of the test is to see if we can get an exact weight of rock per gallon to achieve 100ppm tds over a weeks time - minus the 20 percent water change. And get a 2:1-4:1 calcium to magnesium ratio.

I currently have shrimp stones leeches Calcium and Magnesium Carbonate
Cherty dolomite

Some limestone leeches calcium no magnesium

Acid treated or untreated to remove unwanted dolomite veins. In the for sale section.


Sent from my PC36100 using Tapatalk 2
 

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smeagol, i, personally, wouldn't put them in my tank. Schist is very prone to mechanical weathering, meaning the water will get in between the soft foliation groves and likely split them apart over a short amount of time. Mica schists are weird: Micas aren't exactly clay minerals, but they can act like them. They'll get all over your tank, some clays are "swelling clays", etc., and will definitely cloud your water. Not to mention the possibility of metallic minerals in the schist, such as pyrite (shout out to jrh), blah, blah, blah. If it gets all over your hands just by touching, imagine what it will do to your tank. Sorry, i could go on & on & on. I'm sure you figured out i'm a geologist (who talks way too much). Don't put them in your tank! Happy planting! Ebeth
Rats. I've actually had these rocks in my tank for about a week now. I'm going to remove them immediately. Do you think there's any permanent damage done?

What about the rocks that are commonly sold in fish stores as "petrified wood"? Is that stuff safe to use? I have a little bit of it that I could use to replace the mica schist? But it has a very clay-ey feel to it... Would I just be trading one evil for another?
 

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It looks like petrified wood is primarily silica (quartz). Trace metals can affect the colors, but I think they're bound up in the quartz, so couldn't cause any harm.

Try to scratch the petrified wood with a steel nail and let us know what happened.


Rats. I've actually had these rocks in my tank for about a week now. I'm going to remove them immediately. Do you think there's any permanent damage done?

What about the rocks that are commonly sold in fish stores as "petrified wood"? Is that stuff safe to use? I have a little bit of it that I could use to replace the mica schist? But it has a very clay-ey feel to it... Would I just be trading one evil for another?
 

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Smeagol,
No worries! If it's only been a week, you're probably ok. I'd do a water change and just clean out your filter. You're fine.

Yes, petrified wood it great. Petrified wood goes through a mineral replacement called silicification. There's no organic matter left after this process. Silicification just means that everything has been replaced by silica, which is extremely stable and resistant to chemical and physical weathering. It would take 1,000's of years or more to weather away silica based objects, unless your pH is caustic, like 11.5 or 12! :)
Happy planting! Ebeth.
 

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I removed the mica schist, completely drained all the water, and did a total re-scape using the small amount of petrified wood that I bought on a whim a few weeks ago. I had planned my entire aquascape around the mica schist even though I was suspicious of it from the very beginning. The people at the fish store couldn't tell me its name, and they couldn't even find it in their supplier's catalog to order more when I asked them to. I should've known right then to stay away from it. My guess is the fish store's supplier sent it to them by mistake.

The petrified wood looks terrific in terms of color, but it's proportionally too small for my tank and so it looks kinda pathetic... And yet, somehow I like this new design better. I think I did a better job of arranging the plants this time, despite the inadequacy of the rocks.
 

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Smeagol, I'm really happy you like the design better (despite the size of the petrified wood). You can never go wrong with silica, or quartz, based rocks. When you think about it, it's no different from the quartz sand or quartz gravel we put in our tanks. I'm super happy it worked out, no damage was done, you acted quickly, and you're pleased with the results!
Sounds like a great ending! Happy planting! Ebeth
 

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Thanks Ebeth! One more question: Are you telling me that the rocks called "petrified wood" that are commonly sold in fish stores are actually real petrified wood? As in, these rocks used to be tree branches millions of years ago. I thought it was just a gimmicky name used by the fish stores, a marketing ploy to sell some cheap rocks that look faintly like wood at elevated prices.
 
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