Ebb and flow res heating questions

Grow Cycle
1

Have a 4x4 table and a 75 gal reservoir. Average temperature in tent is 75 degrees. I’m aiming to keep the girls nutes at 68 deg f. My question is… Is there a certain heater/cooler to buy for reservoir? I have this recirculating hot water system. Not sure if this will work? I’m thinking I need something different. I’m not out to save money and end up with issues. Please tell me the best most efficient route to go? I’m planning to do at least 2 more once I get this dialed in. Thank you for experienced suggestions only.

Cheers

2

I’m not into hydro nor do I know anything about those systems but I think
there is talk about chillers and coolers for tanks via hydroponics and the various other methods
of vertical water growing. I think there are some really experienced hydro guys on here that can give you names and brands of the equipment you’re looking for.