the down side is that the system is not a closed loop and you are basically pouring water right down the drain. I got myself a big fountain style pump from HD for about fifty bucks and three gallons of RV coolant (the pink stuff) from NAPA. I have run my machine up to maybe three minutes wide open (DC tig with pulse) and the torch has never gotten warm. The garden hose method I hear has been widely utilized however I have not tried it myself.