Are lake rocks safe for the tank?

[SMcGrath]

I have a little 10 gallon tank and I started off with a couple structures from my LFS and a fake plant. I want to start making it a little more natural, I love the grassy plant look with some cool-looking rocks maybe. I have a baby java fern in there now, along with part of a water wisteria which is actually growing quite well. I had a great idea of maybe building a mini Inukshuk in my tank, in which I could go down to the lake and pick up a few rocks. Just wanted to know if it's safe or not?

[pjaldave]

You can check if the rocks are safe or not by pouring vinegar on the rock. If it bubbles then it is not safe, if it did not, then it should be relatively safe.

Just make sure to clean them well. Never boil rocks. Just pour boiling water on them, or soak in previously boiled water.

[SMcGrath]

great! I definitely want to try that! I'm just a little iffy about it because it will be rocks on the shorelines of Lake Ontario and the water there is pretty bad so I wanna make sure I have safe, clean rocks for the fishtank. Would there be any possibility of a spike that could harm the fish?

[wijnands]

If you suspect pollutants then after the acid test and the boil start soaking them. Soak in fresh water in a bucket. Empty daily and refill. After a week look at the water, if it looks clean test if, you don't get different values than your tap water it's probably safe.

[ScottishFish]

Just be careful when boiling! Some rocks can have a tendency to 'pop' when really heated! Talking from experience here

[SMcGrath]

Okay, thanks everyone for the helpful advice! :) I'll elt you know how it goes and I will take pictures!