I'm gonna go to 100 of cal mag and try to find the balance if this isn't it then idk what else. It alwAys starts a cpl weeks into flower also.
I'm at 1.2 ec and on third week flower. I always get plenty of runoff. Whenever I try to go any higher I get mad high runoff. I'm used to flood and drain where I feed 2.0 in flower. Should I up my base? Idk why I'm having such problems. I really appreciate the help as well bro
It sounds like u may be getting a nutrient deficiency during the 3rd week of flowering everytime, and not a nutrient lockout.
Use the calmag... I assume you know that the calmag MUST be added (and mixed in well) to your water BEFORE adding your base nutes / additives.
Yes, adjust your base nutes because 1.2 ec is far too low for a plant that old... Also, once a plant is forced into bloom and starts going through the stretching stage, it is growing at a rapid pace and needs extra fertilizer (the highest EC of the entire grow should be used during the stretching faze), followed by a big dose of P-K (large PK dose around weeks 4-6, but cut back base nutes when using powerful PK fertilizer)
* You said your runoff is really high if you increase your ec, but how high is it... It goes in at 1.2 and comes out at what ec?