Dwc

Buy a water chiller and an RDWC kit. Gonna run you about a half grand US for a chiller worth a penny. Ice bath clowns have really made the prices go wackier than they were already... RDWC kit...something like the Vevor 4 site. You'll get all your fittings and grommets and a pump and some drip emitters and tubing and valves...and when you only set up 2 of the buckets, you'll have two for incredibly clean swaps if needed. Do not skip the chiller. This is going to be a compressor-driven device that is constantly going at it, likely going through dozens or hundreds of cycles per day, every day, forever...until you replace it or it needs repaired. So if your water volume would need a 1/20 hp, then get a 1/2 hp for posterity (as an example) Don't overthink it. Just buy a kit. It can be fun to do custom builds but the price isnt a reason and access to parts without one of the major hydro stores nearby can be an issue