yea.. not enough light for 40 plants there... you would need at least 2 or 3 45w CFL's per plant to achieve good results

and a standard hepa filter from the store won't handle the odor, esp not from that many plants... i believe the suggested pot size for LR is 2 gallons, but i have seen successful LR grows in 2 Liter bottles

i would suggest making a smaller grow and growing out less seeds over a longer period of time for best results