• Looking to buy a cephalopod? Check out Tomh's Cephs Forum, and this post in particular shares important info about our policies as it relates to responsible ceph-keeping.

Penny is Octopus Tank


Colossal Squid
Staff member
Moderator (Staff)
Nov 20, 2002
How toxic is a penny to an octopus? I looked in Lil P's tank and there sitting out in the open, starting to corrode is a bright penny. I've been watching Lil P constantly since I let him out and never noticed anything, even when I vacumed the gravel for a waterchange. I added a large bubble filter with carbon right after I found the penny. Of course, my little six year old has no clue!!!

Hi Carol,

I think if anything was going to happen it would've by now. Not sure if your penny's have copper in them (our 1 & 2 cents did, we don't have them any more.....instant inflation :x ). Maybe the penny hasn't been in too long, cos I'm sure you'd have noticed it!

In the aquarium if any kids drop something into a tank for eg the touch pools we usually find something the kids don't like and tell them that whatever they dropped in is just like...........(you supply the nasty) to the animals, it works like a charm.....now if we can only find something that will work for ADULTS :evil:


"the cent, once a copper coin, is now composed of copper plated zinc. These cents are less expensive for the Mint to manufacture, and at 2.5 grams each, weigh about 20% less than the cent previously minted of 95 percent copper and 5 percent zinc, which weighed 3.11 grams."

from USmint.gov.... so if its still shiny, its probably the low Cu formula... either that or someone had vinegar and time on their hands...
:smile: Thanks!!!! I kind of paniced when I saw it in the tank!!! It was a 1999 so obviously not totally copper anymore :smile: ! Jess still has not idea, but ya can tell she has some idea that she's not saying!!!

She now knows how fatel any foreign object could be to a creature!! (thanks Jean :smile:

Lil Pumpkin seems absolutely fine! If anything, he totally was all over the large bubble filter with the carbon! Sticking his arms in all the holes! He has decided to keep the pethome as his den! Guess he feels secure!!

Welll for safety reasons, have you removed the penny?I guess maybe it can't be too bad since its already corroded and nothing has happened to Lil P. But still better to be safe then sorry....
Hi Joel!

2 seconds after I saw it, it was out!!! Lil Pumpkin seems fine! Has taken up residence in a conk shell in the front of the tank where he can watch everyone!!

Sponsor Banner
please support our sponsor
advertise on TONMO

Shop Amazon

Shop Amazon
Shop Amazon; support TONMO!
Shop Amazon
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.