I want to use an organic medium and was planing on using organic fertilizers. I have also been looking at teas made with bat guano and things like that. I have to get my grow going one step at a time I plan to grow bag seeds first then later order some real seeds. I have seeds germinating now. I am going for maximum yield so could anyone tell me about how many plants or how big of a space a 250 Hps is good for. I either want to go with a 250 or 400.