I have a Top Fin Silentstream 10 Power Filter with cartridge in my fish tank and it has an adjustable water current. I had it at the lowest water current level and now it's in between the lowest current and the middle. So I would say the strength of the current is at 35%-45% as strong as it could be at its max. Is this okay for the platy fish or do they prefer stronger or less current. I noticed that I have seen two of my platy fish blow bubbles and or gulp at the surface. They don't constantly do this but I have noticed it and I have read online that it could be a sign of not enough oxygen in the tank or something like that. I also have like 8 plants in my tank and I think that is suppose to help out with the water's oxygen. Is this normal behavior to blow bubbles? They've only done it a couple times but eat, scavenge for food, group together, swim all the time, and seem completely healthy.