Is 2.5 gallons' total reservoir space enough?

I'm considering getting the full Bubbleponics system ( SH Hydroponics, Inc. > Bubbleponics™ Pro II - 24 Planter ), putting 4 plants in each 6-planter system, but will 40 gallons' total reservoir space be enough? That's 2.5 gallons per plant.

40 gallons should be just fine, 2.5 each is No Problem.

Thanks, bud. Also, I'm thinking of filling out the whole Bubbleponic system, which means the 40 gallons would serve an additional 8 plants, but all the plants would be smaller (because the added plants would just be to speed up filling out the screen).
Is there anything wrong with this idea? And, would the resulting 1.7 gallons per plant be sufficient, for short ScrOG plants? If jah don't approve, I'm scrapping this re-thought.

[bump] (1.7G per plant sufficient?)