Need help, 2/7 plants unhealthy?

[sugarpuff]

facts:
7 weeks old. 4 weeks into flowering. 3-4 weeks until harvest.
80 cm tall
Ak47+ruderilus...ie auto ak47 (viking ak47)
400 watt hps 40cm from canopy
25-28 degree C
40-55% humidity
using a fan to circulate air
using organic fert 3-1-4, started using in week 3 or 4 at start of flowering. 1/4 dosage then 1/2 then 3/4 and now back to 1/2 cause I heard half is what I should do.
Watering twice/week when soil is dry, using fert each second watering.


Bottom left plant stopped to drink and middle and upper fan leaves dried out and died over night as seen in the pictures, I cut them off it looks naked.
then last week the middle rightmost plants started to get yellow spots on upper fan leaves, some leaves are brittle this plant drinks half as fastas rest of the plants.
Ironicly this plant has the biggest buds and topcola of all my plants.

Question: All plants are treated equally, why do 2 of them act like i watered them with beer and the rest are the undeniable healthiest and prettiest plants in the world?
Whats wrong with them?

The bottom left plant I tried to "flush" but I dont think thats needed cause no salt buildup from organic ferts, so I heard but i heard alot of crazy contridicting stuff:/ Some say burn comes from fert, some say burn comes from lack of fert...
The pot is now super heavy cause of all water and yes I do have drainage holes.
The middle right plants I havent watered since I noticed it started to drink slower, i will wait untill it needs more water.

PLEASE DO NOT answere if you do not know what you are talking about or if you are pulling up plant deficency charts and try to compare, I can do that to and just as alot of people many of the charts contradict themselves to. To many times have i seen people who say A and then equally many comes in and say no not A at all, it is B.

Pictures:

OVERVIEW


BOTTOM LEFT PLANT


MIDDLE RIGHTMOST PLANT


HEALTHY PLANTS

 

[Bublonichronic]

Maybe some plants had a stronger root system and were consuming more so maybe while you were waterin when you noticed them get thirsty you were drowning/burning the slow drinkers...

 

[sugarpuff]

Maybe some plants had a stronger root system and were consuming more so maybe while you were waterin when you noticed them get thirsty you were drowning the slow drinkers...

Perhaps, I have only measured dryness by stopping my finger 1-2 inches into the soil. Impossible to reach the innermost pots to feel the weight of the pots (which is the best way i heard to measure how much water they have left in teh soil) although its 2 of the outermost pots that stopped to drink I didnt know what weight is "correct" cause first time grow anyway

So. possible root rot?

 

[Bakatare666]

Perhaps, I have only measured dryness by stopping my finger 1-2 inches into the soil. Impossible to reach the innermost pots to feel the weight of the pots (which is the best way i heard to measure how much water they have left in teh soil) although its 2 of the outermost pots that stopped to drink I didnt know what weight is "correct" cause first time grow anyway

So. possible root rot?

I kinda agree with Bubble, and checking only the outer pots is possible to create problems, as all plants won't drink at the same rate, and they are always changing as they grow as well.
If I remember the numbers right, #3 and 5 look like burns (and YES, overfeeding causes burns, NOT underfeeding), but the rest of the pics look hungry, but personally, I wouldn't worry too much about it this late in the game.
Your 3-1-4 is pretty weak, and I would say that's why you're getting leaves like #10 and 13, but some discoloration is acceptable as you get close to finishing.
It looks like you might be about 2-3 weeks from done, so if you have something to feed with a little more P and K, go ahead, otherwise, I wouldn't worry about it if it was me.

 

[Medinugs]

I also agree. I would also up the potassium and phosphorus, right about after the stretch they start to demand more P/K right away. Also with an organic P or K nute it takes time to break down and become available to the roots. Add a little drip of molasses to your solution and bubble it 24 hrs at least and it'll be available much faster.

 

[sugarpuff]

My tap water is around 8 ph and is 2.3 dH (german measurement of light/heavy water) according to public information.

Ordered some ph down and a ph meter and some real bloomfertilizers, hesi bloom kompex which will come in handy for the next grow.

The ph is obviously dangerous high which is probably the reason for the necrotic spots? But why do only some plants get affected by it? :S

The Dh levels, is it okey or even important?

 

[sugarpuff]

My tap water is around 8 ph and is 2.3 dH (german measurement of light/heavy water) according to public information.

Ordered some ph down and a ph meter and some real bloomfertilizers, hesi bloom kompex which will come in handy for the next grow.

The ph is obviously dangerous high which is probably the reason for the necrotic spots? But why do only some plants get affected by it? :S

The Dh levels, is it okey or even important?

Anyone knows?

 

[Bublonichronic]

one would think if it was pH issue all plants would be effected? being in the same medium?

 

[sugarpuff]

one would think if it was pH issue all plants would be effected? being in the same medium?

Yeah everything is the same, potsize, soil, water, nutes etc.

The plants themselves are not identical thou, its same strain but different genes ofc Some of my plants are more bushsier and other are taller so maybe genes can affect ph sensitivity? 2 more plants have started to show same syptoms so it is spreading.
I Gave them ph'd water today with no nutes. 6.5 PH. The new Hesi nutes I got is 3-3-4 and got ph stabilizer. Tested to add nutes to tapwater and it got down to 6.7 ph wich is very nice.

Anyways, my fresh tapwater has 8.5ph and declines down to 8.0 after 24 hours. When I used my previous organic fert the waters ph go lowered to 5.5.
The soil is was between 5.5 and 6.5 ph at start
The first 3-4 weeks I only used water and then I used nutes every second watering.

It is now week 8 so I think overtime the soil's ph have rozen to dangerous levels?

Edit: Is Hesi Bloom Complex organic or chem fert?

 

[sugarpuff]

I measured the runoff from both new soil and this old soil that is in use right now. When I run through 8.2 ph water it ends up being around 6.5, when i run through 6.5 ph water it ends up being around 6.5

Guess the ph down and ph meter I bough was totally unecesary lol

My soil however is prefertilized with 11 - 5 - 18, me using 3 -1 - 4 fert at start of flowering and it is bound to show P def in some plants I guess.

This new fert has 3-3-4 which has to be much better.