Rocks

[Cliffz]

Folks,
I was attending a car show in PA this weekend and in the hotel parking lot around the light posts there was this excellent gravel/stone with natural color. They seem to be like lava-with great varying colors. reds and black. Maybe fire formed igneous? Some areas look like lava that cooled. They are coarse and some have micro holes in them making them look very porous.

Question--Are these ok for a planted tanks?
Are these ok for planted tank with Cherry red shrimp?

Thanks -picture attached

 

[newfound77951]

They definitely look igneous with those bubbles.....PA has a lot of interesting geology so they could be local or they could have been brought in as fill (there are a lot of "invasive" rocks all over the place).

They should be OK, but to be safe stick them in a bucket of water, test the pH and kH at the start, then wait a week or two and test again.

They almost look like big chunks of Eco Complete!

 

[Purrbox]

I'd be hesitant to use these rocks in a tank with Shrimp. The coloration in them makes me wonder if they might have copper deposits in them. After checking to ensure that the rocks don't affect the water chemistry by changing the water hardness significantly, I'd ony test the rock with a few test shrimp instead of introducing them to the entire colony.

 

[FMJnaX]

You could also do the muriatic acid test. Pour a little bit of the acid on a sample and if it fizzes or bubbles, you probably don't want to use it.