That's more than enough. I use 11L ones and had no problem.
By the way, my plants have their lower leaves like that these days. I think it is temperature related as they were too low (it's really cold where they are) so I had to put a thermo-vent inside the grow tent that turns on 15min/h so now the temps oscillates between 26 and 30ºC during the day (never measured at night). Just don't know if it is the oscillation itself or hi temps near the floor (where the thermo-vent is). They are huge, that's a fact, and they keep green and attached to the plant so they ain't that bad. Anyway, if anyone experienced this or has any clue, share it please!
Cheers!