Twice a month. One every 2 weeks.

Yes you can grow that many close together just keep them on the small side. Depending on the strain I would start at one foot for flowering.
LOC NAR on probation Reviewed by LOC NAR on probation on . 50 Liter DWC Hi, was wondering how many times i need to change the water a month, also i made the DWC and i've 18 net pots in it...could i grow 18 plants with a 250w hps? Rating: 5