Tristan wrote:

I am going to try and keep a very concise set of records on all ponds
to include a few of the wifes smaller preforms just so I can bump
data back and forth to see how they all vary and what takes place due
to what and when......I have time so may as well make the most of it.

Not being able to aspire to such large ponds as you have, I'd be very
interested in the results from your wife's preforms - as these are more
likely going to be comparable to anything that I end up with.

My assumption on the pre-forms is that the temperature variation will be
less but that the temperature at the bottom will also be lower - so it
would be interesting to see if this theory is confirmed by your
measurements. I also might try and take some temperature readings on the
reservoir of my water feature, which is dug around 18-24" into the soil
- but need to go out and buy another thermometer first as I broke my
last digital one that had a sensor.

Just one other question on the water movement/aeration - if you did this
(ie. aerated from the bottom rather than a fountain on top) in a smaller
pond, such as most of us have/will have, wouldn't it have the effect of
chilling all the water and losing the low level haven that
fish/creatures use to over-winter?

Gill