Regular grow, regular problems....

Ey,

This is my first grow so I am a begginer (keep it in mind pls)....I wanna know weather these plants are females....I had 6 plants 4 of them were very tall and I found out that they were males so they are dead by now...2 of them were smaller but they (in my opinion) had no pre flowers so I thought logicaly that they are female....cause all of the males already showed preflowers...the strain is Durban Poison x White Widow...outdoor I am using only Plagron - Alga Grow + Ph- on water... The plants have about 1 month and 2 weeks....I need also hlp about that, they are very thin and tall pls help me about that thanks....
peace
BTW sry about the shitty photos....

From those pics i can see the sex, but where your male sack came out you will see yellow hairs appear. You can not miss it. Dude out

sry dude but I dont understand....those are 2 plants 1st (it is about 2 weeks younger than on the 4th foto) and 4th photo is the same plant and 2nd and 3rd is the other plant.....both female??? How long till I will see the hairs and the pre flowers? ........ and what about making them stronger with more branches?? THANKS

I can not see the nodes good enough to tell if they are male or female?? The preflowers will have 2 yellow hair coming out of them if they are female and pollen sacks if male. I wish i could help more

Imagine shaved balls(usually in pairs, or clusters), that's a male.

Imagine a hairy bush(white or pink, typically, which turn red/amber/dark red), that's your female.

Your plants do not appear to be displaying sex currently. You have 2-3 weeks before the male pollen sacs explode. So be positive.