Indoor What is this stain?

[insert name here]

I would lean toward Cal mag, I saw similar spots on mine a while back, and added the cal mag and it stopped. What day are they on. I think that I started noticing these around when shortly after they started to flower. Try it I went half strength at first.

 

[philipd]

Yeah there week 5! What u use as a cal/mag supppement? Cheers for the response

 

[insert name here]

I am using AN Sensi Cal/Mg, but I would imagine that any would work fine, I would just start off slow. For me, it was the second day of week five that I added, but the spots started for me around the end of the third week, only after week 4 did I get worried, probably a little late, but they seem to be hardy and took it they almost ready now! Cheers on your grow