# Pudding Stones in Aquarium?



## Farmer (Jan 30, 2013)

Brittenkm said:


> I've got some beautiful Pudding Stones (description below) I've put in my tank but I'm not sure if I should have! I've done some searches here and elsewhere but can't find a definitive answer. Any thoughts? I thought about coating them with something to maybe make them tank-safe.
> 
> Drummond Island, Michigan: Millions of years of geologic process result in puddingstone, a metaconglomorate made up of brightly colored jasper pebbles in a quartzite matrix. Unique to the bedrock of the western end of the North Channel of Lake Huron, it was moved and dropped by glaciers across the Michigan landscape, especially on Drummond Island, and as far south as Ohio and Kentucky. A product of chemical sedimentation and volcanic activity, the jasper in puddingstone is a siliceous rock, colored by metal oxides such as iron and magnetite resulting in the brilliant reds and blacks typical of Drummond Island puddingstone. It was named by 19th century English settlers who were reminded of the fruit-filled puddings of their native land.


From the description it sounds like it would be fine.

Take a bit out and drop some vinegar on it, see if it bubbles. If it does then you should investigate further.

if you want to do a test put it in a bucket of water and see if the pH or hardness changes. 

If it is what I think it is then I have a similar rock i sometimes find in our river. It's a pretty dark maroon colour with spots. 

Do you have a picture?

Linds


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## lochaber (Jan 23, 2012)

All the acid does is test for carbonates.

If the stone is actually quartzite and jasper as in your description, it should be fine.

Possible concerns about metals and metal oxides, but it's probably not worth worrying about.


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## Brittenkm (Jul 21, 2012)

I'll try to attach a photo of one. I am a little concerned about the metals. I'm also a little concerned because my tests show I have really hard water. I haven't tested the tap water yet but I really don't think we have hard water here.


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## GlennR (Nov 6, 2009)

That's in interesting stone.

I collected some beautiful colored stones from Lake Huron, just above Detroit, years ago while vacationing there. They were in a wide variety of beautiful colors, but not multicolored. There were browns, tans, blacks, oranges, and purples all over the beach. They were fine in the aquarium.


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## Farmer (Jan 30, 2013)

lochaber said:


> All the acid does is test for carbonates.
> 
> If the stone is actually quartzite and jasper as in your description, it should be fine.
> 
> Possible concerns about metals and metal oxides, but it's probably not worth worrying about.


Yes, but carbonates are the main reason rocks are not suitable for most tanks.

The vast majority of rocks out there don't alter water much if at all.

Linds


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## Farmer (Jan 30, 2013)

Brittenkm said:


> I'll try to attach a photo of one. I am a little concerned about the metals. I'm also a little concerned because my tests show I have really hard water. I haven't tested the tap water yet but I really don't think we have hard water here.


By the look of that rock it certainly is silica based and I'd be extremely surprised it if altered your hardness at all. For metals to be a problem they would have to exist in a form where they could leach into your water. They are probably bound in the rock. They are most likely what gives it colour. 

If your water is getting harder I doubt it is from that rock. What gravel/substrate do you have? Maybe it has some limestone or such in it. 

You may be surprised. check your tap water. If you live in town you can usually get this information from the council.

Linds


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## Kathyy (Feb 22, 2010)

Carbonates will change the hardness of the water but if you are changing water regularly then there won't be an issue and plants need some hardness anyway. I would worry more about the rock being too soft and crumbling instead which isn't the case here. 

I found a rock outcropping near my house with similar types of inclusions, not nearly so pretty as your rock though. Didn't check it for carbonates as I was assuming all the rocks thereabout were volcanic. Oops.

The very first rock I put in my tank when I was a kid is still with me - in the garden as it doesn't mesh with the rest of the rocks in the tank at the moment. I tested it with a drop of nitrate test solution #1 and it contains carbonates, there is a photo somewhere in the 180 long journal. I never had a problem with it over maybe 15 years in the tank.


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## Diana (Jan 14, 2010)

Sounds like any metals are bound up really well between the volcanic activity and other things that have gone into creating that interesting rock. 

I have some rock in one tank that has actual iron rusting in place. That is the sort of metal that you do not want in an aquarium. The actual ore that changes in the water, and is released into the water. Copper is especially bad. Iron is a plant nutrient, but I do not know if they can take in this form. It is only a few coin sized spots and the tank is 125 gallons. 

Put a few of those rocks in a bucket of tap water. Test GH, KH, pH, and TDS when you start, and every few days for a week. If there are minor changes, then it is probably safe. If there are major changes in the GH, KH and pH (rising values) then the rock is probably fine for a hard water tank, but not soft water tank. 
If the only thing that changes is the TDS, then I would want to know what is coming out of the rock and into the water. 

GH is calcium and magnesium. 
KH is carbonate, a buffer that stabilizes the pH. 
These 2 are generally found in limestone and related materials.


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## Farmer (Jan 30, 2013)

Kathyy said:


> Carbonates will change the hardness of the water but if you are changing water regularly then there won't be an issue and plants need some hardness anyway. I would worry more about the rock being too soft and crumbling instead which isn't the case here.


Though I agree with what you are saying, but it really depends on the rock and the tank conditions as to how much it will change. 

I am commenting on another forum at the moment where someone had some really nice rocks that had carbonates in them (I think it is limestone). They bought them not realising and are now having to change their scape because they are causing changes too fast in his CO2 enriched tank. He would have had to do water changes daily to keep the chem to a level suitable for his goals. 

...

Diana, as far as the iron goes, most dissolved iron is not available to plants directly. The form of iron that is is very short lived in water and more or less has to be use as it forms (from what I have read). It exists in an equilibrium with the non usable for which is much more stable in water. Chealated iron has a longer life but eventually is converted to the unusable type too.

Not that any of this has to do with the pudding stone because I doubt either apply. I'd say it is as non reactive as the glass on the tank lol.

Linds


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