My Jobo 2000 tanks only need 1 litre per 6 sheet reel, I use Pyrocat HD which works out very economic even with that volume of dev.

However you might be better off using a replenished developer, Xtol would be ideal as uniquely you replenish with fresh developer. There one or two recent threads on replenishing Xtol and it's what I did for about 20 years, very economic and consistent and the volume you need in the tank us unimportant (as long as the film is covered).