Help please got a few problems

[Jeff6]

Well first i just noticed that i had some white looking patterns on the leaves, im not sure what they are as there mostly on 1 or 2 plants and say 6 leaves, what first came to mind is mold but i dont know what it looks like so i have took a picture..

Temps: 73-83
Humidity 40-50
Coco Coir medium

I dont test for ph as a couple of people i know have had succesful grows without one, So i decided on not using one this time round, But everything been fine up til now, There at 4 weeks bang on too.

Next problem is this, i had it at the start but it went back green and healthy until now, They are brown on the edges and some tips of a couple of leaves, to my knowledge is this lack of phospurus ? Im feeding coco A + B which is 5-4-3 NPK and im feeding just under what it says on the guidelines which is 40ml of each per litre and im feeding 35ml of each.

And lastly i have noticed when it comes to night time the leaves start to droop, i am feeding every 2-3 days when the coco is a little dryer than moist, I thought it could be just like the plants are getting ready for the night as when morning comes there perked up straight, But i just noticed 1 or 2 NEW leaves that was drooping a bit early.

Any help appreciated as soon as possible thanks

 

[PhishyPhil]

if u wet your thumb can u rub the white stuff off? it almost looks like water or something similar dried up on the leaf. as for the worsening it almost resembles a calcium def, look into some Cal/Mag

 

[Jeff6]

The white stuff you can rub off yes, and i was thinking it was dried water or something but its a but wierd that its spreading more on the plant, and on each leave it has the similar pattern going on the edges of the leaves,

if it is mold how do i treat it, its in flowering now just started thanks