How much solution to develop 4 x 120 E-6 rolls?

I'm using the Kodak E-6 kit and reading their literature. Maybe I am over-analyzing things but I'd like to be sure before I run my first batch in a 4-roll tank.

The guide says: "For best sensitometric results, use no less than 250 mL of each solution per square foot of film (235 mL for two 135-36 rolls)." That implies that I can run 4 rolls of 120 film (same as 135-36 in sq ft) on 500ml of solution.

However, the kit literature then indicates that, in batch mode, after 20 rolls, processing times need to be increased:

"Approximately 10 to 12 square feet of film (about twenty 135-36 rolls) can be processed through a 5-litre sink line using this chemistry in a batch mode. After this much film has been processed, you can increase your first developer time by 20 to 30 seconds and your bleach time from 6 to 10 minutes to process another 5 to 6 square feet of film (about ten 135-36 rolls) with satisfactory sensitometric results.

Processing more film will require even longer first developer times and will result in high contrast images. This may be acceptable for some appplications (e.g. graphics / text presentations), but not for general photographic images. In any case, do not process more than a total of fifty 135-36 rolls in a 5-litre mix of this chemistry."

So, do I, or don't I? Can I do 4 rolls using 500ml as a one-time use without adjusting from standard development times?

might be acceptable

I am in the same boat, figuring solution capacity as I prepare to put an old wing Lycnh into service again. My take on this is that, of course there is a certain amount of developer and other chemicals activity depleted by processing film, but how much?

The Kodak Z-119 manual for e-6 in chapter 2, table 2.1 gives guidance that the replenishment rate for a replenished system of E-6AR (in large tanks) is 200mL per sq foot for developers, 100 ml/sq ft for all else but bleach, and bleach at 20mL/sq ft.

Each 135-36, 120 or 4 4x5 is 80 sq in, so each of these options 'consumes' 110mL of developer at the pro-rated above rate.

I use Paterson reels, and carefully tape the end of one 120 to the beginning of the second 120 to put 2 rolls of film on the same reel to minimize the number of reels, hence solution volume that I put in the processors trough. This lets me process 4 rolls of 120 at once in 500mL of solution as the reels roll horizontally.

Followup: I ran the four rolls and they turned out great. Thanks Mike for your advice.

It also means that I can now get 40 rolls from the 5L kit which is quite economical (about $1.50 per roll).