If you are not finishing directly off your evaporator and then going to the bottling stage then you are wasting your time filtering. Always filter after you have finished the syrup to the right density and then transfer to the bottling stage. If you filter off the evaporator then go to the a finisher to get syrup to the right density you are releasing alot more niter in the syrup while it is boiling. Once syrup is at its final density then filter.