It was my impression that you were supposed to arrange a closed system... with the diesel purge introduced into the rear of the injection pump... and the overflow from the injectors running back into a clear container... so that you could be running on ONLY DP until almost all of it was used up... the reason for the clear container is so you can see when you are about empty and can stop before you suck air into the injection pump....As small as the bottle of DP is I did not think it was supposed to be going through any filter... but someone who is for sure should post soon...