You can do a whole stack of film in a tray, but the first time you do it, your heart will be in your mouth. For one sheet, you just lift one side or end of the tray every minute or half-minute, in the same rhythm as inverting a tank.
I'm assuming it might be helpful to describe this more fully.
A 5x7 tray is ideal for 5x4. Place it in portrait mode and prop up the far edge so the tray slopes towards you. You place the sheets sideways (landscape) and this will cause the slippery sheets to organise themselves in the tray. Sheets floating at random in a big tray will scratch each other.
With dry hands, take a pile of sheets, emulsion side up (some prefer the other way up, so that the emulsion touches the bottom of the tray.) With thumb and forefinger, take the first sheet and place it flat on the first tray of water. Do not slide it in like paper. The corners will scratch the film underneath if you slide it in. With your little finger, push it under. Don't rush. Now the second sheet. Place flat on top and push under until all the sheets are submerged. You now have one dry hand and one hand with a wet little finger and you cannot go back.
Slide your fingers under the stack and remove the bottom film. Place it flat on top and push it under. Do the same for the whole stack, counting as you go, until you're back at the beginning. You might like to do this twice, depending on how much pre-wetting you prefer. The sheets should now be slippery and have a mind of their own
Now take out the whole slippery stack and feed them into the dev in the same way. Start the timer. Shuffle through for thirty seconds, just as you would agitate a tank for thirty seconds. Repeat the shuffling at the same intervals until the time is up. Now do the same into the stop or plain water. Shuffle twice or thrice. Now into the fix. You must be careful when transferring to stop or fix because the contraction of the emulsion can cause the sheets to stick together, so you must take your time. Shuffle in the fix. After a couple of minutes or so, you can turn on the lights.
Begin with two sheets, then four, then six. Six is the most I can manage comfortably but more is possible.
Some people place some sheets with the notch at the other end, so they can be identified and pulled out at different times, for N+ and N- development, but I've never been brave enough. Some people rotate the whole stack and for end, halfway through in the dev to ensure more even development.
You might find you need to adjust your timer settings slightly, but probably not much.
I'm pretty sure that there are members here who can correct or supplement this brief account. They may well have better methods than me.
