What is wrong with my cookies?

[Mangos]

Yo!

Problem: Leaves are looking burnt/ some yellowing and curling. (Problem starts from the top of the plant)
Medium: Plagron light mix
Feed: Only given 1 feed with nutes 4 weeks ago (Sensi Bloom A & B @ 1ml per L) thats when the problem with the leaves started so I switched to just tap water. She has been drinking approx 850ml daily, with a little run off.
Strain: AutoColorado Cookies (50 days old)
Climate: 19.5oC - 25.5oC - RH 40-50%. Growing two plants in a 1.2x1.2x2.0m tent under an Advanced Diamond Series 200W led panel. For ventilation I am using a 4" inline duct fan and a rhino pro cf.

She has had this problem just a over a month now, it has been a really busy time at work for me and I just haven't been able to devote the time to her I would have liked. I am growing AutoBrooklyn Sunrise along side her and she is doing great, no problems at all. Any help would be much appreciated, this is my first grow and I am keen to learn what has happened to cookies so I can hopefully avoid it happening on future grows.

 

[Yeatster]

How close is your light?
It appears you have a couple issues going on. I am no expert but if the tops aren't from LED to close, it may be P def. The rust spots appear to be Calcium def. Do you have calmag on hand?

Experts will chime in shortly

 

[Mangos]

Thanks for such a quick reply.

Light panel has never been closer than 18" and is currently 25". Yeah I have a calmag on hand, I will add to the next feed.

 

[Yeatster]

Thanks for such a quick reply.

Light panel has never been closer than 18" and is currently 25". Yeah I have a calmag on hand, I will add to the next feed.

NP bro. Honestly, wait for someone more experienced to help you. I don't want to steer you in the wrong direction. I suspect you will need a flush, introducing a light feed at the end.

I do have a question though. You say 850ml. is giving a little runoff?

 

[Mangos]

Yeah 850ml-1L gives very slight run off, I do mean very slight

 

[Yeatster]

Yeah 850ml-1L gives very slight run off, I do mean very slight

Unless you are using 1L pots, I think you are watering to fast. If so, this could be part of your problem. Watering fast leaves dry pockets in your soil. You want to water slowly.
Looks like you have at least 3g pots. Those should hold 2L minimum, with no runoff.

 

[Waira]

Mangos-- so all the feeds she had has been just the one light round? I'm shocked she's as big as she is! PL medium is very mild stuff,...... what's your water source?
...looking at those symptoms: the tops with yellow edging and interveinal streaks is Zn deficiency well under way,.. the spotting looks more like Ca defc. kicking in as well,... The lihgt feeding is likely behind this, since she's bigger now, and has really leaned on that soil what little is there,... no surprise to have defc.'s starting! Also, pH in pot is always a factor in play, but with so little going in, badly -off pH seems less likely,.. point is, these defc.' are most likely a lack-off type, not caused by off pH lockout ( chemical changes cause the nute element to be rendered unabsorbable),... Ca is easy to treat with the Ca-Mg supplement, full dosage! The Zn will be more tricky, and you need to feed more regardless, but your nutes will have Zn in them (read the labels carefully to see which in those damn multi-part nute lines) but not likely strong enough soon enough... To deal with certain stubborn immobile nute elements like Zn (Fe too-- immobile means these can't be translocated from established tissues to new growth that needs it more, this is why it manifest at the tops first), it's best to have a dedicated micronutrient supplement; I recommend Earth Juice Microblast because of it's complete coverage, and readily absorbable formulation... treat the soil/medium as directed, and you can also use it as a foliar spray, for both actually, it's the fastest way to get it in there vs. the roots,...but you'll need a wetting agent to make it work well (Coco-Wet is my fav'), or a very mild soap like castille,.. this will take the surface tension out of the solution, and allow it to cover and stick more evenly, instead of just beading up; more surface are covered = more absorbed! Get the undersides of leaves as well, if you go this route,...
...If you're in a buying mood, the very fastest way to deal with this is using Optic Foliars Transport along with the Microblast,... or OverGrow (which has several other things in it),..this stuff "magically" can allow temporary penetration of nutrient go through the otherwise impermeable leaf cuticle; usually he only way into the plant leaves is via the stomata pores, where gas/ moisture exchange occurs... amazing!

 

[Mangos]

Thank you for such a detailed and helpful response. I am having problems finding earth juice micro blast in the UK would you reccomend anything else?

 

[Mangos]

And yeah just the one light feed, using tap water in hard water area.

 

[Yeatster]

@Mangos I'm sure Waira will respond but maybe not till tonight. If you need a fast response to get some now, go to Live Stoners and ask. There are a lot of helpful people there, they will steer you in the right direction.