Possible P def, any idea's???

[TheDude#1]

Hey folks,
Well i think i might have a possible Phosphorus deficiency and also think it may be due to cold temps over a couple of different nights not allowing any P to be absorbed by the plant, because the 1st time i noticed it it was after a really cold night when the temp was 12c and then again just last night when it was 13c. I'll post a couple of pics to see what you all think.
I know i should let my temp get as low but its just the temp changes so much where i live it can be hot one day then cold the next so its hard trying to maintain constants with temp but if this is what the yellowing of my plants is due to i'll make a better effort to keep the temps high!
Anyway my Ph etc is fine, but i also think i might need to start giving more feed as they are going a little lighter shade of green as well.
If anyone has any advice or can confirm this is a P def due to cold weather etc or has any other idea's what they think it is please feel free to comment!!!
Cheers again people!

 

[TheDude#1]

Hey there again folks,
Does anyone have any idea's on what is the problem with the above plants?
Do you think it could be due to to low humidity? Or even due to heat or light stress? Also i use a small fan heater in the dark hours which causes fluctuations in the temps, which sometimes makes temps go higher than daytime temps at night when the heater is on. Do you think it may be something to do with that? If anyone has any idea's please post!
Cheers!

 

[gio77]

Can't believe no one responded in 7 days... they don't look too good brah. You say the pH & EC is okay, though you want to feed a higher dose? What is the current ec/ph at mix & at run-off? How often are you feeding? What is your medium mix? Is the heater blowing directly on the plants?

I see the last 2 pics w severe drying & necrosis... combined with the first pic, they look isolated, near the front of your entrance. It would reason out that the heater is near there & blowing on those leaves the most...? The crispy drying & leaf edge stand-up indicates they simply cannot transpire enough water... usually heat/too much light/too much nutes. K def also contributes.

 

[cyberwax]

Judging by the pics i would say you had an iron deficiency, but your probably just undernuting, atleast you seem to be missing some vital minerals. I dont believe 13c will do that to your plant, as long as you dont go under 0 you'll in theory be fine. I had a mom once who lived outside during the winter, that is; inside a little box tucked away in a shed. Had 35w of lighting and thats what kept her alive, temps were from 4c to 15c, she still lives too. Around 3 years of total age.

But remember the changes you do takes time to show, find a leaf that the deficiency shows on and take a picture, take another 3 days later and compare. But my advice would be to start giving them more food, go up 100ppm pr day and see. Simple is always best, dont overcomplicate

 

[TheDude#1]

Hey Gio77,
Yeah the one that is most affected is by the door and does have the hot air from the heater blowing on it, do you think that it could be because of that?

 

[Row]

Hey Thedude

in response to your message to me

I didnt have huge problems from too high night temps like it sounds you may be having, but it depends how high your night temps are, i can tell you that the plants didnt look quite right and just didnt do so well, loss of vigor, this was because i had above optimal temps for a non co2 enriched room, eg above 78 at night when there was no co2, the day temps were 83-85 optimal for a co2 enriched room.

I have since found that for my sealed co2 enriched room a night temp of 73-75 is best, in the non sealed room i like to stay at 73 and try not to go to 75 so there is still a 5deg drop from day to night.

Some say that you can have a 0 deg drop in a non co2 enriched room 78 day and night, note not a co2 enriched room as you have the problem explained above of having above 78 deg wen theres no co2 at night, the idea of same day night temps is to keep tighter node spacing.

I have played around with iyt a little but didnt find i had good results and it just uses more juice to heat the room up an extra 5 deg.

No dought staying above 70 at night helped my plants do better,

Hope this rambling helps dude,

If the heater is blowing very hot and dry air at the plant then that could deffinitly make the leaves dry and shrival like last pics.

Row

 

[TheDude#1]

Hey Row,
Thanks very much for the quick reply m8!!! Well i kind of thought the same about the temps. And as for the heater blowing against the plants, well it was for a few days, thats when they got a few of the leaf's crisping and drying, so it is now facing away from them, so i hope it stops and dosent get any worse. And i always try to keep me night temps above 70 but now i just want to make sure they dont do any higher to keep them lower than the daytime temps!
So cheers again m8!