Originally Posted by beam2050

yes, your water circulating around your soilless mix would act like a radiator. it would transfer heat to the outside air much faster than your potted plants sitting on the ground where at least at that point they could stay warmer.

but with a 20 gallon hot water heater set on low, a pump and a thermostat you could turn that around immensely. coarse it would take a battery of plants and containers say maybe 6 or 8, a large kids swimming pool and a pool thermostat.
with that you could cover it with plastic making a small greenhouse of sorts and you could keep your plants outside all year long, even in Canada. probably would fruit a lot faster.

of coarse a large in ground coy pond would work much better than a kids swimming pool.