Ernie Willson wrote:

I'm looking at heat pads to put under my seed starting trays. I need
several (say 4 or 5) and they get quite pricey when you also include a
thermostatic control. Do you have any clever ways to provide controlled
heating to your starting seeds that uses other stuff and is less costly?

Those heating pads are often relatively high wattage for the heat they
produce. Years ago when I started veggies from seed in my basement window
I set ordinary incandescent bulbs under the metal shelving.. . a couple 15
watt bulbs under each 30" shelf put out sufficient heat and the metal shelf
spread the heat nicely. I used to raise tropical fish so I had lots of
extra aquaruim hoods that hung upside down under the shelves. I'm sure if
you check the big box hardware stores they'll have very inexpensie reflector
hoods, you'll just have to figure some method to position and to attach
them. Many just clip on.