Sun catfish

So, a few weeks ago, my husband and I were at the store to buy a fish. ONE fish. For our 10 gallon tank. We left with a platy, and a sun catfish. So much for our one fish.... The sun catfish went into our 25 gallon (we will be upgrading here in the next few months or so). Well, I cant be sure that the catfish is eating. We have an oscar and a medium pleco in the tank with him (they get along well enough). I put cichlid pellets in the tank to distract the oscar, and throw several shrimp pellets in for the catfish. I never see the catfish go after the food. He mainly hides in the PVC pipe we put in for him. I also put nori in the tank on a clip. Someone is eating the nori. Im pretty sure it isnt the Oscar (he doesnt seem to like it. He would devour romaine lettuce when I put that in there). So, would the catfish eat the nori? Or is it likely the pleco that is eating it? I also tried live food (I read online that sun catfish will eat live food) but the Oscar eats them all before the catfish has a chance to see them. So any advice?

Here are some pics.

In the bucket we were acclimating him in.



Swimming with the Oscar.

I have a sun catfish in my stepdads 210g that's 10" and it eats anything we put in there! All cats are scavengers so they will eat when they are hungy plus you need to give them time to get use to the tank and yes they do hide a lot! You need to look into a bigger tank soon and that will help! 

Yeah, I know we need a bigger tank. It is in our plans for the very near future. We just "had" to save this guy. He was up for adoption at Petco. We got him for $5! We just couldnt pass him up. Plus he was in their plant tank with a cichlid that had been beating him up.

So, is there anything in particular that we should be putting in the tank for him? Or is the shrimp pellets good? My husband keeps telling me to put some flakes in the tank, but I dont think he will go for those. Plus with how big he is, flakes just wont do.

Do pellets and frozen! Just cuz you don't see him eat when you feed him doesn't mean he doesn't eat! He will eat when he wants to! Lots of catfish like to hide a lot! 

Well, its been a couple months and he is still doing really well!! I *think* I have seen him maybe possibly eat something, but cant be sure. Im pretty sure he is eating the oscar waste, because there is not nearly as much oscar poo in the tank now. I still put shrimp pellets in the tank in hopes he gets some before the oscar does (we distract the oscar with food on one side of the tank and put the pellets in the other side, lol). He seems to be doing good.