I find it interesting how different types of cold and different growing conditions affect plants differently.
What I mean is one plant that can easily handle a hard freeze can sometimes be totally damaged by frost while another can handle frost but the hard freeze kills it while others it depends on other conditions as to whether or not the different kinds of cold will harm it or not.
It seems to me that certain growing methods might be find out in the open for certain crops while other growing methods may be more prone to cold damage. This seems to explain to me why perhaps some people insist that aquaponics must be done in a greenhouse even here in FL. If they were doing only raft aquaponics (even though raft aquaponics may tend to provide for more insulated steady water temperatures, it also seems to be more prone to frost damage. See warm water near very cold air will mean evaporation and then condensation/frost.)
I have grown lettuce in towers without greenhouse protection and had ice form on the plants without having the plants damaged.
These results seem to vary depending on the type of plant some plants seem to suffer more damage depending on how much moisture they are saturated with at the time of extreme temperatures or perhaps it has to do with root temperatures compared to plant and water temperatures along with air/frost.
Still learning but on first glance my media and towers seem to have suffered less cold damage than the rafts. I’ll have to wait to see how much damage the frost actually caused once things warm back up.
Update. Lettuce is all fine.
Only things to take any real damage from cold are the warm weather crops (basil, sweet potato and tomato. And most of the tomato plants seem to have survived the cold only to be beaten by the wind.)
The nasturtiums look rather poorly or at least some of their leaves do but my experience is most of them will be even better after a week or so and probably producing more flowers than before.