If you have a look at the 7.5lt one, the sugar leaves affected by a deficiency, I was thinking of CAL...
Considering I'm pretty close to the harvest time, shall I simply flush and switch to plain water to be on the safe side?
Yes that's most likely a calcium and magnesium deficiency, and that's up to you. It does have majority milky trichs from what I can tell, and one week flush will make more turn.
Up to you if you flush and just use water, i would say go for it but i'm sure others would wanna wait as well 😎