Need help to identify this deficiency

[overbudjet]

How long has this problem been going on? Since transplantation
What system are you running? Under Current
What STRAIN are you growing?White Widow Dinafem
What was the establishing technique? Seed
What is the age of your plants?30 days from seed
How long have they been in there mixture they are in now?15 days
How tall are the plants?15 cm.
What PHASE are the plants in? Veg
What Technique are you using?LST
What substrate/medium are you using?Hydroton
What is the Water temperature?65-68
What color are your roots? White Are your roots slimy?no
What Nutrient's are you using?General Hydro FloraNova Grow

What is the TDS/EC/PPM you are using?Water start at 90 ppm+50 ppm Cal/mag +450 ppm FN total 590 ppm
What is the pH of the "Tank"?5.6 ---6.0
How often are you testing your pH/PPM/EC/TDS?daily
Are you sure your calibration is correct on your equipment?yes
What is your water temps?65-68
How often do you clean your system:Each 2 weeks
What size bulb are you using?600 Super hps hortilux on Quantum digital
How old is the bulbs you are using?100 days
What is the distance to the canopy?10inch
What is your RH Factor?55/60 light on 45/50 light off
What is the canopy temperature?75-80
What is the Day/Night Temp? 75/80-----70/75
What is the current Air Flow? Sealed room
Is the fan blowing directly at plants?Yes partly
Is your water HARD or SOFT?soft
What water are you using?tap
If using tap water, what is the ppm/EC/TDS of the water right out of the tap?90
Has plant been recently pruned, cloned off of or pinched?Yes topped at 4th.node
Have any pest chemicals been used? no

 

[overbudjet]

So nobody have any clue about these pics!

 

[Sat X RB]

I defer to the knowledge of those who post below ...

 

[joe fresh]

LOOKS LIKE SALT BUILD UP/PH LOCK OUT

 

[SeaMaiden]

You think so even at a ppm <600?

OP, where on the plant is this necrosis occurring?

I personally think that you're going to need to shift the pH lower, firmly in the 5s range. You're in the coco coir range and while I haven't used Hydroton or rockwool, I have grown in soil, coir and pure perlite and pH ranges need to be different for each media (outdoor organic soil using soil food web methods has needed no mucking around with those parameters).

 

[PoopyTeaBags]

5.6-6.0 is fine for any hydroponic medium coco and rdwc included...

 

[Hydro-Soil]

Have you checked to make sure you don't have a 300% strength bottle of cal/mag? Evil crap.

Try bumping your mix to 700 and drop the cal/mag... you already have 90ppm water, have you tried just not using the cal/mag?

The other issue I see is pH. This is undercurrent, correct? The roots are constantly in contact with the solution? Then you should run you pH swing like NFT/DWC/SWC and all the other systems that have submerged roots... start at 5.2 and let it rise to around 6.0 before dropping it back down with nutes.

Huge difference.

Now... if you were using some nutrient that wasn't as closely balanced for cannabis I'd say try to keep it between 5.8 and 6.0... while dumping it every 2 weeks. LOL

Stay Safe!

 

[overbudjet]

Thanks all ,first i grow in UC and RDWC since 4 years now and i have enconter numerous set back(learning curve).First time with this one!
Necrosis seam to start in the older leaf and slowly raise.Leaf darken and after some time 2-3 day rust and white spot appears and leaf became crispy(dead).I will try to take plant pics tonight.

 

[overbudjet]

You think so even at a ppm <600?

OP, where on the plant is this necrosis occurring?

I personally think that you're going to need to shift the pH lower, firmly in the 5s range. You're in the coco coir range and while I haven't used Hydroton or rockwool, I have grown in soil, coir and pure perlite and pH ranges need to be different for each media (outdoor organic soil using soil food web methods has needed no mucking around with those parameters).

The necrosis appear in the lower part and raise slowly.When you said firmly in 5s range do you mean 5.2-5.3---6.0 . Hydro-soil is saying the same think.So 5.2-5.3 with Floronova grow and no cal-mag.

 

[Hydro-Soil]

Yep... 5.2'ish.

Without a meter I just hit it 'around' the 5 color. LOL

It's the slow rise through the ranges to 6.0 that allows the plant to feed on everything that's there.

I'd also chuck the 'grow' unless you're growing trees. Stick with the "Bloom" through veg and flower... you'll get more dense/compact plants that will yield the same... less height is all.

Stay Safe!

 

[overbudjet]

thanks HS i will try only bloom this round and i will start at 5,2 and let raise to 6.0 i will also raise ppm to 700 no ca/mg.

 

[SeaMaiden]

Over, I haven't ever seen anything quite like that. If those were upper leaves, the answer would be easy, a Ca-. But lowers changes the picture. So I'm going to attach a flow chart that I use to help me get stuff figured out, as well as a graphic of cannabis leaves. Unfortunately, the graphic artist forgot to depict Ca- cannabis.

Ok, so, just looking at this set of images, one could end up considering a Mn (manganese) deficiency. What I don't know is where that typically occurs on the plant. Nor do I know whether it's a mobile or immobile element. Guess it's time to get some learn on!

So, here's a page from plantphys(iology) dot net. Scroll down to Mn (manganese). Please remember that this information is given in an agricultural context, but I wouldn't be surprised if it's also to be found in, say, a greenhouse ornamental context. Also, I'm not saying unequivocally that what you're experiencing is a Mn-, but I do think it's worth consideration. You'll probably want to read the whole thing.
http://5e.plantphys.net/article.php?ch=t&id=289

Manganese. These leaves (see Web Figure 5.1.B) show a light interveinal chlorosis developed under a limited supply of Mn. The early stages of the chlorosis induced by manganese deficiency are somewhat similar to iron deficiency. They begin with a light chlorosis of the young leaves and netted veins of the mature leaves especially when they are viewed through transmitted light. As the stress increases, the leaves take on a gray metallic sheen and develop dark freckled and necrotic areas along the veins. A purplish luster may also develop on the upper surface of the leaves. Grains such as oats, wheat, and barley are extremely susceptible to manganese deficiency. They develop a light chlorosis along with gray specks which elongate and coalesce, and eventually the entire leaf withers and dies.

Guess I can't post up the pic.

 

[overbudjet]

I will read these for sure Sir!
My first guess was iron but with the chart and pic Mn seam very likely
to me.What will cause manganese def.Taken from Mynamestitch Guide to sick plants.
Manganese (Mn) Micronutrient and Immobile Element


Manganese Helps enzymes break down for chlorophyll and photosynthesis production, as well as it works with plant enzymes to reduce nitrates before producing proteins.

Having plants that are deficient in manganese can turn the young leaves into spotted (mottled) yellow and or brown areas on young leaves. Dead (Necrotic) yellow spots form on top leaves, while the lower older leaves will or may have gray specks and or spots. Symptoms can include yellowing of leaves while the leaf veins can stay green. Can also produce a chequered effect. As the plant gets newer growths the plant will seem to grow away from the problem, that’s why the younger leaves may be unaffected. On the top of the leaves, brown spots can appear. While the severe areas of the leaves turn brown and wither. Parts Affected by a Manganese deficiency are: Young leaves.

In this case all leave are young 30 days from seed .But the def. seam to start by the lower leaf and raising.So it's not corresponding to the description.But pics do ?i will take other pic tonight all plant!
Thank for helping a puzzled Grower!

 

[overbudjet]

Also thanks for the link!