Rock for my aquarium

[fissyfriend]

So my sisters went on vacation over spring break and they went to Oregon and they got me a few things from a store they went to. They got me a Sea Side T-shirt, a little bag of colorful rocks and a little bag of shells. I was wondering if it would be safe to put the rocks and shells in my 10 gallon freshwater tank. I have 2 neon tetras, a golden mystery snail, and an African dwarf frog. I can't find any information about store bought shells being added to an aquarium but I know I can't go to the ocean and get shells rinse them off and put those in my tank. Is it going to be safe if I add the store bought shells and rocks?

 

[Andrew McFadden]

if any of it is coated then I wouldn't do it