Rock/Stone gathering. All pass the vinegar test but...

[MartyMA]

So, I have been slowly gathering 'found' stones to add to my SA biotope build. We have an abundance of both river and ocean stones and have been picking up most from the beach. I figured if something survived the ocean's pounding for millennia, it should be good enough to sit in the bottom of my tank. I have tested every stone (we are not talking boulders here) and all pass the vinegar test. However, some have looked suspiciously discolored, almost rusty. I figured that maybe a magnet test was in order. I did discover some magnetized stones - some slightly and one very. I am presuming there is metal present and that is not good. Is there any merit to this? I did look at a local garden center since some suggest that aquarium safe stones can be found there. Everything way too big and most of the slate had rust bands running through. I need an opinion about magnetic rocks and stones.

Thanks.

[MartyMA]

Anyone?

[PlantedRich]

Some may depend on the size of the tank and how you operate. Also how reluctant you are about hazards will figure in as well. I don't worry about metals in my tanks. I often have steel items which rust and let metal flakes fall into the tank. Not everybody feels this way.
I do lots of water changes to keep the fish healthy and to reset the ferts I add. Rocks degrade really slow in most cases. They are hard as rock, right? How long has the rock been around? Most would agree they are at least a few million years old and been outside most of the time. I figure they will last as long as I need them in my tank and likely will not release much more iron than I will get off the shafts in my filter impellers.

This is a clamp on my tank canopy that is dropping rust. I don't worry the question.

[Amandas tank]

Originally Posted by PlantedRich

Some may depend on the size of the tank and how you operate. Also how reluctant you are about hazards will figure in as well. I don't worry about metals in my tanks. I often have steel items which rust and let metal flakes fall into the tank. Not everybody feels this way.
I do lots of water changes to keep the fish healthy and to reset the ferts I add. Rocks degrade really slow in most cases. They are hard as rock, right? How long has the rock been around? Most would agree they are at least a few million years old and been outside most of the time. I figure they will last as long as I need them in my tank and likely will not release much more iron than I will get off the shafts in my filter impellers.

This is a clamp on my tank canopy that is dropping rust. I don't worry the question.

You have a bike tire in one your tanks don't you? I think it's you who has that awesomely-unique scape! I loved that one! How many years have you been keeping fish? I'm just curious because you don't mind about rust I think you must be quite seasoned in the hobby.

Anyway, back to the owner of this thread I too collected rocks and have been wondering the same as you about the metals and rust. Never thought to do a magnet test. Will try that one! I will be following this thread to see what others have to say.