All syrup after in season packaging, as long as you filtered it when putting into bulk (5 gal. plastic up thru any larger size) should be reheated and filtered again if there is any hint of cloudiness in the product. If there is no cloudiness you can skip it, but I just do it as routine.
When I re-filter, I still use all of the plates (I only have 5 sets, 7" press), but I use less DE. I charge the filter with 1.5 cups in about 3 gal. Then I run about 5-6 gal batches with 1 cup DE per batch until all is filtered. To do this, I use my finisher, heat the whole barrel worth in that, then I draw off the initial 3 gal, 1.5 cups DE and run it. Then I draw in 5-6 gal batches, add 1 cup DE and run that, repeat as necessary.
If you are only doing 5 gal total, if you can heat that all at once, try 2 cups DE and run just as a single batch. If you need to do smaller lots adjust. Back when my filter press only had 3 sets of plates I ran about 1.25 cups for first batch, then about 3/4 cups after that per batch.
You can use just 3 plates if desired, I prefer using my full 5 because the pressure is easier to control and the job is done quicker.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.