Prevent getting worse leaves colour

https://plagron.com/en/tools/grow-schedule-calculator-flow

I think that is not lack of Nitrogen. If was that propably the bottom leaves would yellow first. Maybe is overwatering or light stress? We can't say 100%, in any case let the soil dry well and ckeck your light source just to be sure. Good luck!!

The tips edges yellow to brown, medium is past its recommended EC threshold, 1.8ms/cm or above, (too much salts) prevents bulk flow, crippling calcium uptake via osmosis, and forcing active transport of nutrients rather than using bulk flow. A few things are going on, and a lot of what I see is from the big 3 cations (Ca,Mg and K) and a possible antagonism, along with high EC. From the nutrients you listed, I don't see anything standing out as the main culprit. Terra Bloom is higher on potassium than I'd like that early in flower. Right now, she is more looking for P than high K from terrabloom, possibly leaving too much potassium behind, causing a lockout of sorts on Ca and Mg through antagonism. Very possible to have a skewed pH, too. Have your plants always been that droopy or was it only after they got sick? Loss of bulk flow can fcuk transpiration, which could explain the limp leaves. IF they have been droopy longer than I'd be seriously looking at your medium, as I see a lot of red/purple stems, this is normally linked to P deficiency, which most of the time occurs from low oxygen levels in a medium. Give her more a 1-3-2 right now than a 2-4-4. Losing calcium and phosphorus instantly destroys a plant's ability to convert carbon to sugars/energy. No Bulk flow, no active transport, nothing, no transpiration = droop = no cooling. Gluck