I'm novice, following books by Dave Miller. I prepare 6 gallons of water in advance, boiled 15 minutes, put in sanitized glass jugs and refrigerated. Last two batches had water out of fridge, 3 gallons used for boiling wort, 2+ added at the end of the boil and then used an immersion wort chiller for cooldown. Got things down to 75 degrees, then even an ice water bath resulted in glacially slow progress down to 70. I am thinking about trying using the chiller just on my 2.5-3 gallon wort, getting it down to just above my tap water temp and THEN adding the water from the fridge to get it to 65 degrees. But I am wondering if the addition of water needs to happen at the higher temperature of the boil, or if water is water and dilution of wort can happen at any stage. I seek and will listen to the wisdom of those more experienced than I. And I thank you for your time in reply.