20 feet is enough, but 25 or 50 is better. The difference you will see with the various lengths is the amount of time it takes to go from boiling to pitching temp. The faster you can cool your wort to pitching temp the better. The cold break will be more pronounced and your beer will be less cloudy. You also expose your wort for less time to possible infections from stuff just floating around in the air like pollen. So a 20 footer will do, but 25 and 50 are much faster and if you ever decide to do a 10 or more gallon batch your time will suffer considerably. Have fun!!!
What do you mean "no Kidneys"???, WTF now I gotta drink less beer...
Join the Automation sub forum in Electric brewing for a discussion of components and control systems. I did!!!!