That should be sufficient, as poly is especially good at removing soluble metals. I hate to say I'm still up in the air about whether or not carbon will effectively trap antimony. It should bind to other elements that would be trapped by carbon, and thus removed from the system with a carbon change after 72-144 hours.
If you used ABS material in your 3d printer, this may well have contained antimony.
I don't know how Triton Detox functions, but if it's a chelant, it will bind antimony just as it would arsenic or any other metal.
As I keep coming back to this post, I'll close with this, there's not a whole lot of research done to effectively study antimony and it's effects on marine and aquatic environments. Almost everything I've read has to do with inhaled or ingested variants of antimony trioxide. This is not the form you're most likely to find in a water source with available calcium, sodium, or other elements to bind to. Those would be tetravalent antimony and calcium antimonite.
So far the best resource I've come across, which even notes it's own gaps and flaws in methodology is a Canadian groundwater study specifically regarding antimony.
You can read it in it's entirety here.
