big leaves getting slightly rusty

Hello mate, for my experience the condition of your leaves seams like a problem with the rate of Calcium and Magnesium in your water; when you use organic product you have to be careful about this rate, you want it in the range of 3-1 or 4-1 Ca-Mg. I noticed that until you are in the veg phase you haven't issue, after one/two weeks of flowering the leaves start to be like yours, crunchy and with some little brown spots; i didn't solve the problem until i checked the rate of Ca/Mg and fixed it in my tap water. I hope to be helpful, good luck and happy journey!!

I would calm down with the nitrogen and consider adding some calcium.

This is the beginning of nitrogen toxicity from being way over fed.

Og ja ph værdi af 80 procent af dit udbytte hvis ik der står rigtigt 😳✌️. Men vi snakker minimum v dig hvis ik den er ok og det ik jern mangel. Du kan jo give den omgang stress down. Fra xpert nutriens eller andre. 😉. Det har jeg haft go effekt af. Plus de giver dig et gratis gødnings Kit når du er på growderiars.com og skriver du er meget interesseret i at at prøve kræfter med deres gødning og om de har et sponsor Kit fik et sidste år og i år os m hoodie strømper alt muligt ekstra. Og du MÅ GERNE SKRIV DET NICOGREEN DER HAR ANBEFALET DEM TIL DIG. XPERT NUTRIENS.. JEG GARANTERE DU BLIVER GLAD FOR DET. ❤️

For meget fugt meget normalt på denne årstid, du kan også godt fjerne de ALLERSTØRSTE OG MØRKESTE BLADE SÅ DU FÅR MERE KRUDT TIL BUDS BEST REGARTS NICOGREEN OG SELV SAMME PROBLEM I TIDEN PGA DET LORTE NORDISKE KLIMA. MEN DET SKAL NOK BLIVE TIL EN GOD PIGE SOM VIL GØRE DIG GLAD, MERE END EN GANG (HVIS DU FORSTÅR SÅDAN EN LILLE SØNDAGS JOKE HEHE 😉 👍🏼 ❤️ GOD HØST NÅR DU ER DER :-) 💚💚💚

No worries bro, she just got too much moisture for a long period of time.. Humidity is too high.. maybe check your ventialtion its also Phosphorus deficiency (too much iron inwater? Uptake of phosphorus is much poorer when the water contains much iron...) maybe check your PH too, its maybe a bit off good Luck!