I currently have my water 4-5 inches below the brim of my tank (198litres) so that my precious Blackmoor gets enough oxygen. Is this okay? I've ordered a water pump and will be getting her a friend (she's by herself since my other fish died) so I'm just kinda doing this in the interim. She's not moving much/eating much and is hanging out INSIDE the plants at the middle of the tank. All water tests were good so I'm wondering if oxygen might be a factor.