CO2 and Plants

[TKOS]

So I have this question that has been annoying me. I know that when you add CO2 to your setup it is important to minimize surface aggitation so the CO2 levels stay in your tank. I get this.

However, I often see or read people giving advice that any planted tank must have minimal surface distortion. That if you don't add CO2 you still have to stop the distortion so that CO2 doesn't escape.

But isn't that combining information? Isn't it that if you don't have CO2 added that you want some surface movement to promote better gas exchange and get CO2 into your tank? Am I wrong?

I see so much conflicting info and really just want to understand what the heck is going on. In my planted tanks without CO2 I have surface movement and my plants grow fine.

[wetmanNY]

Yes, you're identifying a widespread fallacy. Water movement at the surface can only bring the water's dissolved CO2 into balance with the partial pressure of CO2 in the atmosphere. Temperature figures too, of course.

Depleted water will absorb CO2. Supersaturated water will outgas.