Looks like youre growing guerilla style. Maybe consider organically amending the soil so you dont have to worry about applying nutes. I used a super soil at home this year that ran from the start of May thru September. Since i grow organically i used garden lime as a pH buffer and assumed that it had Cal/Mag as well. It does but not like Rock Phosphate & Langbeinite. That combo right there is great for flowering plants and supplies the Cal/Mag needed as well. I use the DowntoEarth line of amendments. There is a ton of other stuff i use. Some would not be wise for guerilla growing as it could attract varmints. The Rock Phosphate and Langbeinite will not. Just my $0.02 bro.