This is probably the first CHE I ever used, Incandescent light bulbs were the mainstay heating device, didn't know anything about ultra violet rays,light was light But when these were found you had heat without all the light, the wire glows but doesn't produce much light.Light bulbs during the day, heating elements at night was how it was done.Today it is pretty much done the same,but with much better lighting and safer heaters.I think I saw my fist all glass aquarium in 1974. Any one else have memories from back in the day? Len