Pond Boss Forums POND CONSTRUCTION Creating habitat Pond vegetation

In another thread, there is a discussion about High PH in ponds which I find a very interesting subject and I've been digging into it some. One thing I�m finding in my reading is that, although submerged pond vegetation increases DO, it is reducing CO2 at the same time which will result in an upward swing in PH; with the amount of the upswing dependent on several factors. My pond has High PH (8.3 to 8.4) already and very high alkalinity (250-300). I don't want to go from an "ok" PH situation to one with unacceptably high spikes in the afternoons just because I planted/allowed vegetation.

My questions:

1) Does emergent and/or marginal vegetation increase DO and reduce CO2 to the same degree as submerged?
2) I�ve been planning to try and get some submerged vegetation started for habitat and nutrient control. Is this a good idea, bad idea or �it depends� for my situation?�
3) Should I focus on emergent and marginal vegetation instead of submerged?

Any insight anyone can provide would be greatly appreciated!

Bill D.