Using fresh wood in a tank

[knifegill]

Most fresh deciduous wood is fine. The white slime is harmless and many fish will eat it with joy. But the juglone in some oak species is pretty nasty stuff. It's used as a dewormer in low doses, higher doses are definitely toxic. Always research the EXACT species of wood you plan to use, search the web by adding the wood name with words like 'toxin' and 'medicinal', be creative.

Fresh conifer...you might as well just dump pesticide in there.

 

[Kinbote]

I'd found some plum wood that looked perfect for what I'm trying to create; started baking it to dry it out and then found out plum wood basically contains cyanide. Awesome.