Don't you have the instruction booklet that came with the filter press? If not, call Smoky Lake let them know your problem and I'll bet they will ship you an instruction booklet. For just 2 gallons of syrup use about a half to 3/4 cup of DE and put your blocking plate behind, as you said you were going to do run it back into the syrup you are drawing from until its clear then you can put it into your bottler. Once done use really hot water and if you have the hand pump model just a couple of pumps will clear the syrup out of the press. Then a few more pumps and you can put that back into the evaporator. I then run water thru mine until its clean.
2004 - 2012 2x3 flat pan 25 to 60 taps
2012 2x3 new divided pan w/draw off 55 taps
2018 - didn't boil surgery - bought new evaporator
2019 new SML 2x4 raised flue high output evap. 65 taps
made 17 gal. syrup
2020 - only put out 53 taps - made 16.25 ga.l syrup
2021 - Didn't work out
2022 - 25 taps on bags / 8 taps on 3/16's line - late start