When we got over 100 taps on the star ladder line it wasn't working good enough for me. Someone on here was talking about vertical pipes. We switched to that one year, worked better, then "Tim" came out in me & wanted "more power" so added the dry line loop which does seem to help. Not sure if its when froze. but certainly when the sap gets running good. Vacuum does get stopped at bottom "waiting" for sap to come up tubes.
Murray
Somewhere around 800 - 900 taps on Atlas Copco vacuum
1 Sap Ladder & 1 can
2 1/2 x 10 Waterloo/Small, with Piggyback & hood,
Air over & under fire
CDL autodrawoff, Homemade drawoff/filter tank with pump,
Lapierre Sirofilter, modified steam pan bottler