What kind of system are u running? Regardless, luke warm water is not good, mainly bc baddies like the warmth but we don't like baddies in our nute solution.
Sounds like a chiller is a must for u. The size will depend on how many gallons u need to cool and how much temp pull down u actually need. Most brands start at 1/10 hp and go up from there but remember to always get the next size larger than u need. There are alot of manufacturers of quality chillers. If u have a smaller garden, an activeaqua (hydrofarm) or ecoplus (sunlight supply) should work fine and those are available at any good grow store. For bigger gardens, or with those with deeper pockets, JBJ and chillking are tops in my book. Don't forget ull need a pump too.
Good luck!
