"Tom L. La Bron" wrote in message
...
Bill,

If you are worried about "aesthetics" and airstone pumping air into your water
from the bottom of your pond would probably be a better idea, especially as
the summer is coming on and higher pond temps, especially in Austin, Texas.
The airstone in the depths of your pond would allow a lot more "air" to come
in contact with the water than just moving it up and and across the surface
using the pump.

Tom L.L.
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Newbie Bill wrote:
I have a small 200 gph pump (very low power usage) submerged in my pond for
additional aeration - just as added 'insurance'. The output is below the
water so the water is just 'bubbling' like a natural spring might. I do not
want it splashing for several reasons. I have been told it is the breaking
of the surface which helps to oxidize the water.
Questions: 1) Is this actually doing me some good. 2)Aesthetics aside would
an airstone attached be significantly better.
Thanxx
Bill Brister - Austin, Texas


Actually, the air water interface is at least as important, if not more
important. The larger the surface area of the air/water interface, the greater
the exchange of gases. While an airstone can pump air through the water, it
does so in a limited way, since it is only making contact with a small area of
water at a time and only influences the immediate area around the airstone. By
inducing a current across the surface of the water with a pump located at the
bottom of the pond, you will induce more gas exchange because of the greater
surface area involved. It also helps in preventing zonation from froming in the
water column, since you are pumping the water from the bottom and streaming it
across the surface, which in turn, allows oxygenated water to move towards the
bottom of the pond. The ripples going across the surface of the pond also looks
nice.