When you want to............if ya got the space and light ........how big do you want it. My She Shed is in cellar (sativas tricky ) .......doable.....and I'm so sick of indica (skunk) up North here.Hey Krew. I’m new to Hydro. Trying an Old skool Strain of Panama Red. Sativa all day long. I love Gardening! Nothing like Homegrown Vegies! This is my First MJ grow, I’m trying a DWC, using Foxfarm Trio (hydro formula. Learned real fast! Thx) as well as the powder BB CC & OS. My babes are Feminized Strain 5 Weeks ole tomorrow (since the day I put seeds in Water) anyway no problems yet. I just curious about when to Switch from 18/6 to 12/12 for Flowering? Let me know what you think.