Hey Mike,
Nice country there in the Shenandoah Valley. I use to live in Stanardsville on the other side of the mountains ,but that was 26 years ago.
The soaker hose seems to be working out good, but it's only been in 6 weeks. I used weights to keep it down, but it wouldn't lay flat, so i filled a garden hose with sand, and zip tied it to the soaker, that did the job.
The plug-in thermostat works on air temp., and it has a heat, or cool switch so you can have it turn on, or off at any temp you choose. it also can be programmed for different settings on different days, but thats too complicated for my short attention span. i got the thermo. from Amazon.
There probably aren't many people with trout ponds down there, how big are your trout, and how deep is the pond?
There are alot of hatcheries in penn. that sell Tiger trout, you might even find some closer. they are definitly more agressive than either my rainbow ,or brook trout.
Good talkin to ya.