Cooling the Nutrient Solution

[omerizm]

I need to cool down my NS. It peakes at 30 degrees celcius in very hot days. I grow lettuce and recommended temp is 24 C.

I'm thinking about using the return water from the cooling pads, which runs at 20 degrees.

The idea is, put a pump in the cooler tank, pump it through some tubing insterted in the nutrient tank, return heated water back to cooler tank. Use a thermostat to maintain temp. What do you think?

And, can I use copper tubing? Will it do any harm to the plants? If yes, what else can I use?

Thanks in advance.