Is Catskill-pa Bluestone Aquarium Safe?

[celaeno]

i found an auction on ebay for 30-35 lbs of Catskill-PA Bluestone. the seller claims it's aquarium safe, but is it really?

i did a few minutes of research and it appears that bluestone is sandstone, which the first post in this thread says is best avoided:

link

EDIT: here's a pic of the rocks

 

[NutMutt]

Just have to watch out for the wrong minerals leaking out. Do you have an empty 10 gallon to test it out with???

 

[celaeno]

Do you have an empty 10 gallon to test it out with???

nope. besides, how would i test for dissolved minerals? also, i think they dissolve gradually over a long time, if they do dissolve. but thanks for the reply

 

[celaeno]

i am worried about the rust-like appearance of the rocks.

 

[MisterBullfrog]

On the link page you provided the slate sample picture is actually Bluestone, Go figure. I can tell by looking at the side view and how it's layered (just like the ones I sell). PA Bluestone is form of slate and is named for it's unique blue hue and less organic composition. It's from blue clay that washed into the prehistoric "metamorphic rock" mix of the Catskill Delta. It is not a sandstone and will not dissolve or crumble. I've tested it with hydrochloric acid and 20 years of aquarium use. The brownish tint is only on some of the rock surfaces and can be sanded off without reappearing. It Has been harmless to my fish but I'm going to test it anyway. My personal use has found this rock to be inert.

 

[SJ2K]

Sorted looking good, always handy for me to read posts like this as it'll prove invaluble for a future mbuna attempt.

 

[MisterBullfrog]

I did some research and put together some useful information about these rocks.

Geological:
A metamorphic sandstone of the Appalachian Plateau. Formed in the Devonian Age.

Texture:
Fine to medium grain.

Chemical Analysis (from a local quarry business):
Silica 77.80%
Alumina 8.40%
Iron Oxide 2.86%
Titanium Oxide .52%
Calcium Oxide 2.27%
Magnesium Oxide 1.20%
Alkalies 2.13%
Sulphur Trioxide (SO3) .13%
Loss on ignition 2.64%

This is a chemical analysis of black slate (found on the web).
Calcination loss 6.5%
Silicon 55.7%
Iron Oxide 6.3%
Aluminum Oxide 17.4%
Calcium Oxide 0.7%
Magnesium Oxide 6.3%
Potasium Oxide 2.6%
Sodium Oxide 1.8%
Sulphates expressed as SO3 Inf 0.6%

Quite similar in comparison and both are a metamorphic rock.

 

[kribensis12]

Someone has done their research!

 

[Luketendo]

Iron Oxide 2.86%

Isn't this toxic to fish?

 

[MisterBullfrog]

I don't think iron oxide is dangerous in small amounts and the bluestone analysis shows less then that of the slate. It's used in fish food most likely as a coloring agent. Fish would get far more from these feeds then they would from the rocks. Iron oxide is also used as a phosphate absorbent in marine tanks but not sure about freshwater use.

 

[celaeno]

iron oxide is aka rust. i very much doubt rust is a fish food ingredient.

 

[MisterBullfrog]

iron oxide is aka rust. i very much doubt rust is a fish food ingredient.

Google it

 

[celaeno]

i see it and i don't believe it. iron oxide is an ingredient in wardley's betta food and ocean nutrition's formula one. D:

 

[Zeoth]

Wow. looks like Bignose has some competition.

 

[MisterBullfrog]

Google "Aquarium Cave Rock" to find my auctions for these if you would like some for your fish.