Are bubbles needed?

Here is a list of questions I would appreciate if someone would go through and answer.

1. Are bubbles needed to help get more oxygen in the water?
2. Would placing the output of powerheads/filters closer to the surface of the water help with getting oxygen into the water?
3. How do you know if your water needs more oxygen or not?

I'm just curious because I have a bubble stone going in my 75gal tank and I want to remove them because they take away from the feel of the tank, and I can't hide the damn wire going down to it well enough.

Advice/tips/etc needed

 

1) No

2) Yes

3) you can buy a DO meter if you think you may have a problem. Otherwise, if everything looks happy and healthy, you have enough.

A few decades ago, before powerheads were invented, it was believed that the water absorbed O2 from the bubbles. While we know better now, we also realized they did provide circulation and surface disturbance which are important for optimum gas exchange. They do, however, provide fresh air at the water's surface for tanks with lids/hoods.

 

Thanks Bill