Hi everyone,

I am growing 3 plants indoors and unfortunately I have been facing few problems, I am assuming that my first plant has a potassium deficiency, which I am not sure if it has stopped or not. my 2nd plant is really dark green and today I have noticed a spot on it, which I have no idea what it exactly is. Please help! and advice me for the future and now

I am growing using:

200w light.
water PH: 6 to 7
Fertilisers: biobizz, grow, bloom and fish mix (I only started using it 2 feedings ago)
light schedule during flowering: 18-6
light schedule in the beginning: 20-4
soil: https://www.bauhaus.info/tomatenerde-gemueseerde/floragard-bio-tomaten-gemueseerde-lecker/p/27215593

Thank you so much!