# Is this rock safe for shrimp..



## 8062282 (6 Jul 2015)

I've just starting a planted tank & have some rock which I want to use to keep some red moor down. Any idea what the red/brown streaks are?  I would like to add some RCS eventually..

I've done a vinegar test & there's no bubbling...

Thanks in advance, Jules


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## EnderUK (6 Jul 2015)

probably, better test would be to get a bucket of water, measure the TDS, leave the rock in for a week and then measure the TDS again.


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## 8062282 (6 Jul 2015)

I haven't got a way of measuring the TDS. Do you need a meter? I did have several of these rocks in a tank with danio & minnow & they were OK for the time I had them. Any idea what the red/brown streaks are?



--
Stay Happy


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## EnderUK (6 Jul 2015)

My guess is iron oxide but that is just a guess. You can pick up a TDS meter for about 5 quid off ebay or amazon. The TDS pen will tell you how many solids are dissolving into the tank over the week. It probably won't be a lot.


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## 8062282 (7 Jul 2015)

Hi - OK, thanks. I was looking at these last night. Wasn't quite sure if they were up to much because they were quite cheap. Will invest in one. Thanks for your help..


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## EnderUK (7 Jul 2015)

The TDS ones are pretty accurate, two electrodes that measure the conductivity of the water then convert it roughly into total dissolved solids. Better then sticking you're finger in and having a complete guess.


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## dw1305 (7 Jul 2015)

Hi all





EnderUK said:


> My guess is iron oxide but that is just a guess.


My guess as well.

cheers Darrel


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## zozo (10 Jul 2015)

Definitely should test it.. but it could be simpel boulder clay looking like iron oxide. I once found a simular (nice looking) stone and it was boulder clay. Still have it, don't know if i ever gona use it, maybe in something planted without livestock first. Because i still don't know whats in the clay. It dissolves rapidly if muriatic acid is added to the water and leaves a clay powder residue, doesn't realy react on vinigar in just clean water it also looks stable even when boiling, but don't know what it does to the water in the long term submersed. Boulder clay is in the stone since the ice age it formed, so can be rock hard and deep with in the stone.


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## 8062282 (10 Jul 2015)

You could be right. I tried scraping at the streaks with a knife and the stone seemed powdery. I've got a TDS meter so I'm going leave the rocks in water for a week or so & then test it.


--
Stay Happy


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## zozo (10 Jul 2015)

hopefully it works out it's a nice looking stone, looking like it has a mystery history and a story to tell.. 

Looked bit different when i founf it, more dirty, redish brown too, thought i could wash it off and got mad and obsesed with it.


 
Chiseled glass hard brown clay pieces of it, cooked it, tried a rotary steel brush, dremmel tool, it had glass hard and also softer areas it was definitily clay.. vinigar did nothing only heavy acid pulled it out as a silky brown powder that also felt like clay when wet. I left it for days in the acid, but its deep in the stone impossible to get it clean.  The stone has won i had t give up.. Because it did react to the acid i still not comfortable with it to use it as hardware for the long term.

If a week doesn't show anything i still would try something like muriatic, or phosphoric acid to see if it reacts.. If it does the chance that it in long term will react in slight acidic (soft) water as well.


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## 8062282 (11 Jul 2015)

I'll see how the water tests in a week or so. I did have several in a 160l tank for a while & the fish were OK....


--
Stay Happy


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## zozo (11 Jul 2015)

Ok!?  i mean to say if it ever was a soft clay deposit where the stone was in for who knows how long. Wath ended up in the cracks and in the pores of the stone and then compresed and dried again for who knows how long. it may could take many months for the water to soften it up again and make it slowly leach out. This could not only affect EC values but also hardnes and alkilinity or even other organic compounds. You don't want to have fluctuating to much. normaly clay deposits in boulders like that are from grind sand stones and other stones grinding each other for thousands of years to powder and forming a clay mass around the boulders. I called it simple boulder clay but still you'll never know what kind of cocktail is in there. The process is simple but the contents might not be.

If you have a nice collection of stones like that could be very beautifull and unique. Usualy you find only 1 among many others and are difficult to harmonise with other stones. Maybe i'm a bit to paranoia, but i would be cautious and test the water with such stones for months to come with more than just EC before putting anything else than plants with it.


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## 8062282 (11 Jul 2015)

Thanks for advice. I wouldn't want to risk my shrimps in anything I wasn't happy with. I'll try a plant only tank & see how it goes for 2/3 months. Thanks again..


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## dw1305 (12 Jul 2015)

Hi all,





8062282 said:


> I wouldn't want to risk my shrimps in anything I wasn't happy with. I'll try a plant only tank & see how it goes for 2/3 months. Thanks again..


 I think it is probably inert, but it is more likely that the rock would reduce pH, rather than raise it.

The reason would be that the iron oxide staining might come from the oxidation of iron pyrite crystals within the slate? matrix. If un-oxidised pyrites remained its oxidation would release sulphuric acid (H2SO4).

cheers Darrel


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## sparkyweasel (15 Jul 2015)

EnderUK said:


> probably, better test would be to get a bucket of water, measure the TDS, leave the rock in for a week and then measure the TDS again.


And if you put some _Daphnia_ or _Cyclops_ in the bucket you will find out if the rock is leaching anything toxic to crustaceans


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