I have the daryl sheets press its a 5 inch and i usually run about 8-9 gallons at a time through it per batch.
for my press with all the plates in it. i charge the heated to 200 deg. syrup with 3 cups of DE i use a wisk to mix the de into the syrup when mixed i place the suction hose and the jar filling hose into the syrup kettle and start hand pumping.
Recycling the charged syrup through the press and back into the kettle. this heats the press and fills the chambers in the press with the proper de bed for complete filtering. I would say i hand pump if for about 3-5 min. then start filling jars.
In my mind you need enough de to create the proper filter bed for how many plates you use for your size press. it is not based on how many gallons you run through it. on my sheets press i think the void plates are 3/4" thick and the perfect bed is 1/4" de per side with a 1/4" gap in the middle, this gap will allow for a batch with lots of niter. Before i filter i let the finished syrup sit for a couple days to let the niter settle out so the syrup i filter has a low niter amount in it.
Tim Schmidt
2013 13 Taps 4 Gallons Syrup, Drum evap.
2014 50 Taps 14 Gallons Syrup, Drum evap.
2015 60 Taps on 3/16 gravity, 40 Taps on buckets, 42 Gallons Syrup, Home built 30 x 60 arch and flat pan
2016 125 Taps all on 3/16 gravity average 18 in. vacuum, 43 Gallons Syrup, Same Arch and Pan
2017 125 Taps all on 3/16 gravity average 18 in. vacuum, 44 Gallons Syrup, Same Arch and Pan
2018 155 Taps all on 3/16 gravity average 18 in. vacuum, Same Arch and Pan, home built 100 gph ro unit