I use a 10 1/4" inch,dual layer fine mesh strainer on top of mt fermenters, straining out hop & floury grain gunk. It also has the added benefit of aerating the wort as well. I then top off to recipe volume with spring water that's chilled in the fridge a day or two before brew day. Chilling the wort to about 75F or so in an ice bath before topping off with the chilled water. I get it down to about 65F or so.