Safe Rocks

Hi
I like to find out if these rocks/stones is safe for aquarium. Got them at plant nursery. Lost of pple use them to decorate pot plant. I have placed them in water and ph seems the same.

 

Hard to say exactly what rock that is from just pictures... hell, I'm definitely no geologist so I probably couldn't tell if they were in front of me either!

I've used stones from nurseries before, but it is a gamble. You can't exactly be running around their property doing the vinegar test (putting vinegar on the rock and seeing if it reacts - a fizz means that it will likely bring your pH up a bit). You can try this test out at home, and although it isn't definitive, it is a good start.

Rocks that easily break and crumble are also likely to come apart and leach material into your water column.

Be aware that some garden facilities are quite liberal with their use of pesticides, so anything you bring home from there should be scrubbed and soaked (repeat as necessary) before use.

As you've done, check the pH, but keep doing it over the period of a few weeks. Remember that rocks that are liable to break down in water will do so in the presence of decreased pH, not necessarily in tapwater where acidic agents might not be present. This therefore might not be a fast reaction in tapwater, but may have more rapid effects in your tank.

Soaking the stones for some time can also be a useful indicator. A change in pH is one thing, but a change in the colour/milkiness (and sometimes even the smell) of the water is a sign that the rock isn't holding up well in water.

 

That looks like a bleached quartz. If it is it will be safe, it's extremely hard and not porous. If you have a pressure cooker give them a good hour under pressure.

 

Isn't it calcite ?

No Cory no glory

 

Out of interest has anybody performed the vinegar test and then had the rock/stone change the PH heavily?

 

I just soak it in vinegar, if there is any fizzing or bubbling, then it's a no go.

 

Back when I lived in a soft water area, I regularly tested rocks that I found all over the place. In some instances I kept them (limestone I believe? Could be wrong) because I was keeping Rift Lake cichlids, so helped to achieve the water I was looking for.

 

Good info, thanks @SalmonAfrica

 

If you bought those stones from a nursery, there should be a label on the packet of what they are, otherwise someone working at the nursery should be able to tell you, as they have to know what they order..