Welcome to Tropical Fish Keeping forum.
I moved your post out of the old thread and started a new thread of its own. It is always best to start a new thread with a specific issue, as more will see it and you will get a better response.
To your question, can you give us a bit more data. Tank size, other fish, and substrate material. How long have you had the two Pictus Catfish? Have you tested for ammonia, nitrite and nitrate, and if yes, what are the numbers? How often are partial water changes done, and how much volume?
Is there a reason you are keeping the tank cooler at 70F? The Pictus Catfish would probably be a bit better slightly warmer, around 74-75F. BTW, we have fish profiles with such info on each species, second heading from the left in the blue bar across the top; if the name shades you can click that for the profile.