I have a 25-ft copper immersion pre chiller that I use with my plate chiller. I brewed last week in 100 degree texas heat and I was only able to the wort temp down to the mid 80's. This was using a very low flow rate from my march pump. I was thinking about adding another chiller in series. I have a metal recycle yard close by that sells rolls of new 50-ft copper for scrap prices. The question I have is whether or not geometry makes a big difference in a pre chiller? Could I just leave the copper coiled up and solder fittings on?