Possible problems with leafs

Hello, I grow 1st year and noticed some issues i guess.



As you can see on 1st picture, there is probably some deficit of some element?!

On 2nd picture, there are some brown areas, I was told it looks like spongy mold :/

So i just want to ask: 1) how to solve this?
2) 2nd plant is going to finish (I would say 1 week left), so should I just let it be?

Need more info, soil, hydro, lights, nutes, ph, temps etc.

Well, 1st plant is Wappa, I have 3 of them and its on all of them. They are in greenhouse since June. Soil is based on some basic nutrients (idk which are exactly included), I havent been manuring during grow cycle, but I started manuring during bloom cycle, I bought Terra Max (1-5ml/1l water) and ive been doing it frequently last weeks (cca every 3 days) but weather wasnt always optimal these days and soil is still wet after last suffusion (5 days ago!) so maybe its because too much water? Temperatures are very unstable, but its mostly around 15-24 C. Unfortunately, I dont have pH meter so I really dont know pH value, but we have own high quality water if it helps...

2nd plant is something from friend, idk which strain is it, but she will be soon finished, im growing it in same soil and flushing her, but she is growing outside, behind greenhouse...