What do these brown stripes on leaves mean?

Potasium definici . Bro go flush now and give nutrients .

Looks like nutrient burn. But also looks like phosphorus deficiency. A flush was the right thing to do. After that use half the nutrients your using. Its better to starve a plant then to over feed. Its easier to fix and not as stressful for the plant. Make sure your feeding according to the manufactures guideline( ration wise. ml/l is dependent on what your plants eating ). From what I see your adding way to much "Tiger bloom" it should be half as much as the grow big you add. Happy growing

According to your feeding chart, you are using 6 ml of calmag. If so, please flush once, then keep it at 1ml per litre. Otherwise it locks out the other important nutrients and it won´t matter the nutrient quantity. Remember, sometimes less is more.

Ola amigo tudo bem ? A meu ver parece me que foi regas com ph desregulado. A dose de nutriente que das pode não estar correta. Deves fazer flush sim, fazer uma rega com ph regulado, atenção para não adicionares nutrientes a mais. Pois também parece que ela esta com um pouco de queima de nutrientes. Boa sorte no resto do teu cultivo e abraço