Wow!
I would have though these pet stores or LFS would be selling tank decor or products that would be safe to use inside a tank!
Otherwise its a kind of a contradiction!
Or simply put, maybe some stores or some LFS are just after your money and are not particularly bothered about what happens after you leave their stores with their products? I know thats kinda cynical but that really is what happens sometimes.
By looking at threads like these, its a good thing for others to see this so they should now be wary of buying decor that could be detrimental to your tank and/or stocking if are not careful!
Probably would have said that most LFS or aquarium safe decors are safe enough but need to be on the lookout for certain things like possibly types of paints, plastics, ceramics, and chemicals used in the productions of these that could turn out to be toxic.
But how would you know what to look out for if there is nothing on the product itself?
The stuffs on LFS or pet store shelves usually only have a price tag and maybe a brand tag or something like that.
Perhaps if have a marking or labelling that show they are aquarium safe then that should be ok to use in your tank.
I would not really know the differences to be honest so it might be a good idea to have a pinned thread that kind of shows dangerous products or ingredients or something like that to show people what is safe and what is not safe to put in an aquarium.
For example -
I have learned that 100% cyanoacrylate is usually safe for glueing plants to bogwood for example.
Smooth glass should be fine as long as it is not / or does not contain - antique (old glass commonly has lead), paint, unsealed mirror, lead crystal.
Ceramics - if it is not safe or cannot be used for humans to use for foods or drink then it is probably not safe for aquariums.
Green wood is not safe for aquariums.
But branches long dead from hardwood trees like oak CAN be ok but need to be made safe by boiling and soaking for some period of time to kill bugs and beasties inside the wood.
I do not know anything or know very little about plastics, terracotta, rocks, slate, shells or corals so cannot comment about those or if these can be used in aquariums.
Please do feel free to correct me or add to on any of these as I would dearly like to learn about that sort of thing. Very interesting!
Perhaps may start a thread with this sort of information.........