is this normal?

[Bubble]

it said here: 340 GPH. I have 2, so that add up to 680GPH. Take out some so I should have around 500GPH. Hope that enuf. But I will take out few small parrot.

Given the fact that oscars are prone to hole in the head disease

I just check and saw one tiny hole in the head of my big oscar. What kind of medicine should I buy?