Fiber or RC?
I wash in tray. 8x10 in 8x10 tray and so on. I have extra trays to use. I only wash a couple at a time. I don’t let water run continuously, rather change it a few times. I use two trays as I continue to process, moving the washed prints to a second tray.
Large prints, 16x20 and larger I only do 1 print at a time.
Info to maybe help:
It’s not a strict time number or changes of water for me. It seems to work just fine. Maybe it’s because I only use RC paper now.