4x5 in Combi-plan tanks, but not the standard way. To avoid the long drain/fill times, I use three tanks, but I don't use the "dip-n-dunk" method with 3 tanks as I found I could not get consistent negative densities with that method. The following method greatly improved my results.
I Load film in the "D" tank, when ready to start, turn out the lights, remove the "D" lid, put film in the "D" tank, lift film holder up and down for 5 sec, put the "D" lid back on, develop and agitate by inversion method with lights on.
One minute before end of development time, turn lights out, gently remove lid at the proper time, transfer film from the "D" tank to the "S" tank for a 30 sec continuous agitation bath, lights are still out.
Finally, transfer film holder to the "F" tank, put the "F" lid on the tank, turn on lights, fix normally.