I would fathom a guess that hot water is "lighter" than cold water,
therefore if you had a 100' of hose, and one end of it is in 25' of
direct sunlite (and had been for a period of time) about 20 degrees
hotter, the colder water would push the hot water a little higher in
the tube... dunno ... never experimented ... If you initially held
the sight tubes side-by-side and leveled the water and marked the
tubes... then stretched out the 100' of hose (some in sunlight, some
not) and staked the sight tubed into the ground to measure from the
sight tube marks down to the dirt, I would imagine, after a period of
time, that it would be possible for the "hot" end to be higher than
the sight tube marking, while the other end may be a little below the
sight tube marking.
Ken.

Please explain why.


"Harry K" wrote in message
. com...
"StveB" wrote in message
news:Do1hc.65237$U83.2385@fed1read03...

I've been checking this thread watching for another warning in
addition to the bubble problem. ALL parts of the water level must be
at the same temperature. Half in shade and half in sun can also throw
your marks off.
Harry K