Need help identifying the problem, pics included

[mNz6]

Hello guys,

I have 10 plants from bagseed that are about a month old. they all are showing the same symptoms. here's my growing conditions:

Medium: 50%-30%-20% Peat moss-fine perlite-vermiculite for seedling stage then moved to 50%-30%-20% peat moss-coarse perlite-worm castings and a bit of powdered dolimitic lime

Lights: CFLs to start then moved under a 430W enhanced spectrum HPS (BLV-USHIO 2100K-58500lm) with an air cooled hood.

Ventilation: about 250CFM

Temps: 27C lights off - ~33C lights on (A little bit too warm but best I could manage in the hot/arid climate of my country)

RH: 25% - 45% (Again, best I could manage in my homemade setup)

Runoff pH 6.5~6.7 (tested by pH strips and a high quality pH meter pen that is ATC capable (automatic thermal compensation) calibrated weekly.

Water: Distilled and pH'd to 6~6.2 using 3% nitric acid as pH down

Nutes: Homemade mix using high-quality dry agricultural fertilizers that give the following profile @TDS .7, (pH'd to ~6 with 3% KOH solution as pH up and fed to the plants once a a week between two waterings)

N: 196 ppm (20% of which is ammoniacal N, about 10% Urea-N, the rest is Nitrate-N)
P: 85 ppm
K: 293 ppm
Mg: 48 ppm
S: 56 ppm
Fe: 0.8 ppm
B: 0.2 ppm
Mn: 0.46 ppm
Zn: 0.29 ppm
Mo: 0.035 ppm
Cu: 0.17 ppm

EC/mS : 1.39
TDS @.7 : 973

Now the plants were growing fine until two weeks ago when they started to show yellowing in the lower leaves, at first I thought it was N deficiency so I increased the N in my profile but it didn't help. next I thought it could be a salt buildup so I flushed them and restarted the feeding schedule, still no luck.

Now the problem is moving up in the plants and there are also some necrotic lesions on the yellowed leaves and also some yellowing and burning on leaf tips and ridges.the yellowing progresses rather slowly but surely. other than the yellowing the plants seem to grow very compact with the nodes less that half an inch apart in some plants, more in others, but still very compact. Also the leaves are a bit droopy but I figure that can be because of temps.

Here's some pics from two of the plants, the quality is not that good but I can provide better if need be.

Thanks in advance guys

 

[moresntoil]

Looks like they are starving to me, try increasing your n-p-k a bit, but first transplant to bigger pots for sure.

thats what I would do....

good luck friend

oh, I dont see any calcium listed in your nutes and your using distilled water so you might want to add some, just I thought.

 

[RetroGrow]

IMO the problem here could be your mix. First you had 100% soil less. Then you changed to soil less , except for 20% worm castings. I don't like that mix. How do you treat it, like soil or soil less? Sounds like you are using a PH for soil, but it's 80% soil less, which would call for a lower PH.
I would first try lowering the PH to 5.8 and see if there's improvement. With soil less, you want to feed with each watering, like it was 100% perlite or coco. I think you would have been better off with all perlite, or perlite/vermiculite (80/20), like in hempy buckets. Your mix makes the PH tricky, and I think you have some lockout. Your pots are big enough, but I would have used hempy buckets with just perlite/vermiculite. If you move to bigger pots, I would scrap the earthworm castings and peatmoss. Otherwise, the 20% earthworm castings don't provide enough nutrients.
So, I would lower the PH and increase feedings as though it were soil less.

 

[mNz6]

Hi
Thank you guys for the advice
@Retrogrow:
I will be transplanting my plants into bigger pots today or tomorrow...as soon as I figure out what to do about my medium.
I wasn't too happy about the worm castings either for the same reasons you mentioned, but the reason I used it was because the only kind of fertilizer available here in my country is the dry agricultural kind and all of them have Urea as a component and as I understand Urea is undesirable in soilless systems as it needs to be broken down by bacteria before it can be absorbed so I added the worm castings to create a sort of micro-fauna and not really for the nutritional value...I don't know if it was a viable solution so feedback is really appreciated.

I water the plants with water/nutes ph'd to around 6 which is a little high for soilless and a little low for soil...it was the best I could think of...the runoff comes out at ~6.5-6.7 mostly because of the worm castings which is alkaline...do you think I would be better off scraping the worm castings altogether and take my chances with Urea not being absorbed?

@moresntoil: I have a bit of dolimitic lime (CaMg Carbonate) in my medium which is supposed to take care of Ca and Mg to some extent, but if you think that is not enough I can foliar feed the plants with something that has Calcium...

Thanks again guys

Cheers

 

[RetroGrow]

Yes I would scrap the worm castings and go with 80% perlite, 20% vermiculite in hempy buckets. 100% soil less.
Read the thread on hempy buckets here:
http://www.icmag.com/ic/showthread.php?t=98419
Very simple. All you need are buckets, anywhere from 2-5 gallons.
The bigger the buckets, the bigger the plants. In big buckets, give them a longer veg time, topping the plants two times and you will get huge bushy plants. If you want smaller plants, just use 2 gallon buckets. Even 2 gallon buckets will produce large plants. You won't have any fungus gnats either with all that perlite, in my experience. Then PH them @ 5.8 and you will see phenomenal growth. Hempy buckets are really passive hydro, without the hassle of pumps or plastic tubing. The hempy bucket should be watered daily 'till runoff, which comes out of a single hole you drill 2 inches from bottom of bucket. Very simple & fool proof method to get great yields.

 

[mNz6]

Thanks Retrogrow, I like the idea. I will throw a few of my plants into a hempy setup...will update on how they progress...I just hope my nutes will work in this setup 'cause it's difficult to find different ferts here...