Hi guys today I brought a feather fin catfish , so far (past 4 hours) it has been doing really well in the tank and shows no signs of aggression .however I also have a red tailed shark ,who apart from a couple of barbs who he chases is peaceful too. I'm just worrying as I only have one cave area which is like a divers helmet and the shark lives in there ,but the catfish has also been in a few times. I guess I'm just worrying they won't be able to share and may get stressed. I have had the shark a few years and he's doing great. I would really appreciate any tips for the feather fin as it's the first I have owned.

Thanks for the reply , so far he's doing well just a tad shy still but that's ok :)
I've recently been looking at larger aquariums so maybe one day in the future I'll upgrade ,I'm making sure if I do I do it properly and don't rush into it. :)