Yes, they are the same fish.Is it the same fish?
It looks like physical damage, possibly from fighting or swimming into something.
The fish in the middle picture looks a bit skinny and unhappy.
I think these pair got him, should I move the eggs to somewhere else?Are there any suckermouth catfish in with the discus?
Because some catfish will try to latch onto the discus if the catfish are hungry.
Can’t I just turn off the filter and add a sponge filter in?What and awful spot to lay eggs. Can you move the filter to the other side of the tank but leave that intake tube there?
You can't rear discus young away from their parents. Some places do but it is hard. You need to leave the intake tube with eggs where it is and move the filter to the other side of the tank. That way when the eggs hatch, the babies won't get sucked up the filter.
if you can add an established sponge filter that is fine, but if you add a new filter and turn the old one off, you will have ammonia problems.Can’t I just turn off the filter and add a sponge filter in?