I have a few plants in there, he doesn't like to mess with them at all. However the plants are dying because I do try to keep a low lighting setting in his tank since he's not really a fan of bright light. I'm having a hard time giving them enough nutrients the keep them healthy and thriving so I might take them out altogether. I just read that puffers love some coverage and I wanted to accommodate for him. Has anyone had any luck with two partners in the same tank, I know it's a risk. But I'm wondering if there's some way to introduce them properly. I did think about getting some smaller fish but at the moment I feed him Rosy minnows so I don't think that would be a good idea as he would just see them as a floating snackWelcome aboard!!!
You could definitely try keeping the plants as long ss they aren’t super fragile sincd some puffers do like to rescape their homes...
As for tankmates, honestly probably something like Ottos would be the best bet since they are cheap and stick to themselves normally...
Otherwise, you could try other small, fast moving fish but in a 40G it doesnt give them much hiding space unless there is a lot of nooks and crannies for them to hide in / under that the puffer cant reach...