Is this enough oxygen?

[Jesseliu13]

I have this old Tetra AP 300 on my 300 gallons. It says its rated for 300 gallons but i wanted to be entirely sure that it is enough for the tank. I also have a 2260 GPH pump with a antisiphon hole that intakes oxygen into the current to increase oxygen, not sure if it helps though. Should i increase my flow?

 

[softturtle]

I wouldn't rely on any air pump to really supply air to a large tank. IMO, surface agitation is king. All my returns dump into my tanks. It's noisy, but never see my fish gasping