seedlings dying second to third set of leaves

[indoorpsychs]

Hello people.I have a serious problem after some succesfull grows.Every seedling dies second to third node from iron/sulfru like deficiency.At first i thought i overwatered.So i changed what i knew.Started experimenting,less water,more water,different nutrients,different ppms,different ph,different medium,light far,light close.Everything i do the seedlings die.They all exhibit the same deficiency.I have been experimenting with over 40 seeds,starting over and over again but nothing seems to work.Only 1 seedling wasn't fully affected,managed to survive that i will try clone because this girl is made of iron!!!After all this time i stumbled uppon a thread about grow tents killing plants from offgasing.And the symptoms i have are the same exact as those from people having problematic tents.And my tent is also new,3 months old,so it might be a huge coinsidence and i am trash grower or 2022 and there are still tents that kill plants.Sorry if i made vocabulary and grammar mistakes,not my native language.Any help or thoughts would be highly aprreciated.I will include some pics.

 

[GMT]

I'm tempted to auto assume it's the wrong compost, but what kind of light are you using?

 

[indoorpsychs]

i am using a 600w hps with a dimmable balast.Haven't come to the new age yet.The medium is not compost,just peat with some minerals for the first week as the company states but i wasn't using any nutrients till day 15-20 before.the medium is plagron light mix and the lights where dimmed down to 300w providing 7-9 k lux.Temps in the closet 23-25 lights on-18-20 lights off.oh,and something i forgot to mention that is so strange,never found anything on the net about this.the plants don't grow side nodes.Either the sick ones or the one that managed to survive.I topped it because it was healthier than everything else but before that there was no side nodes even after 2 months.The sick plants grew like a new set of leaves avery 2 weeks but it was growing white in every seedling despite the feeding ec.

 

[GMT]

That's far too much light for seedlings, esp if they aren't 100% happy with the medium. You shouldn't need to be feeding them at all at this stage, both peat moss and even plagron do have nutes in them, so adding other stuff to the mix may be causing a major lockout.
Were you feeding due to them yellowing or because you felt you should? Trying to work out which came first, the yellowing or the feeding.
If it was the yellowing, find another compost, if it was the feeding, stop it, flush and wait.

 

[exploziv]

what can you tell us about PH/ EC? Seems weird, Fe def would show when PH is high, yet peat is usually very acidic. Could you be overfeeding nutes? Any soil mix should have enaugh nutes to move them further along with no problems.
Last advice.. when nothing else makes sense, make sure you are the only one "caring" for them, and they're not helped somehow to get this way.

 

[indoorpsychs]

when the yellowing started i start the very light feeding.Didn't fix anything.So i blamed my ph meter,changed the prob.Still nothing.Then i bought another bag of same soil.Same.Then i bought biobizz light mix,same same.Then i changed nutrients,Remo,GH,AN,recomended doses,low doses,high doses.Same and shame.Its being 3 months and over 50 seeds.Last 2 grows in the same medium whatever i threw to the plants they ate with happines,just didn't overdoo it.I was growing DTW.I went from 0.6 ec to 1.5 full bloom.Didn't have any problems.The only thing i have changed is that i moved to a new house in a near neighborhood and i bought a new tent because the old one had light leaks.

 

[indoorpsychs]

what can you tell us about PH/ EC? Seems weird, Fe def would show when PH is high, yet peat is usually very acidic. Could you be overfeeding nutes? Any soil mix should have enaugh nutes to move them further along with no problems.
Last advice.. when nothing else makes sense, make sure you are the only one "caring" for them, and they're not helped somehow to get this way.

I am the only one caring for them.I will attach pics from hydrobuddy from my
previous succesfull feeding regimen and even what i have tried on them to no avail.The ph of the substrate of course went down from the feedings,you are completely right they didn't need nutrients at 12 days old and i even use tap water which has plenty of iron even for the early veg.But low ph should give me a micro toxicity.Those who get feed 2 ec,those who get feed 0.8 ec and those i dont feed have the same appearance.Feed from 5.6 to 6.5 to different tests.I have tried everything.The only thing i haven't tried is growing one outside.Just before 2-3 days i came uppon a thread about the offgasing effect and i don't have another light yet or a lightproof room.

 

[indoorpsychs]

That's far too much light for seedlings, esp if they aren't 100% happy with the medium. You shouldn't need to be feeding them at all at this stage, both peat moss and even plagron do have nutes in them, so adding other stuff to the mix may be causing a major lockout.
Were you feeding due to them yellowing or because you felt you should? Trying to work out which came first, the yellowing or the feeding.
If it was the yellowing, find another compost, if it was the feeding, stop it, flush and wait.

Is 7000 lux too much light for seedlings?Even if it is do you see the stretch?It is because i thought the same thing,my lux meter is broken and i am burning them,can't have iron deficiency so young.So i moved it like 5-6 feet above.No change.Then i moved it closer.Again the same.Look at the stretch of the healthier seedling the one that made it through but not completely healthy or growing as it should.

 

[GMT]

I take it you've done a soil autopsy to rule out root invaders? You're ticking all the right boxes and coming out with a fail, I must admit I'm stumped.

 

[StickyBandit]

Maybe try a seed in organic seed mix with no added nutrients as a side by side to determine where the problem lies?

 

[troutman]

Keep the pH below 6.5 and you shouldn't see iron deficiencies.
Throw a couple of iron nails in your water bucket if you can't
get nutrients with enough iron in them.

 

[indoorpsychs]

I take it you've done a soil autopsy to rule out root invaders? You're ticking all the right boxes and coming out with a fail, I must admit I'm stumped.

i am stumped too.no bugs in the room.maybe one or two gnats at some point but nothing else.and 3 months now can't find an explanation.

 

[indoorpsychs]

Maybe try a seed in organic seed mix with no added nutrients as a side by side to determine where the problem lies?

done that with biobizz.same results.

 

[indoorpsychs]

I will water them with some distiled water next time to see if its something with my water till saturday that i will disasemble the tent so i can see if its the culprit.for one thing i am sure.growing with different parameters but exhibiting same deficiencies it have to be something common to all of them.the water the light and the enviroment are the only things they share and i changed my new bulb with the old one i had already grow plants with so light is out of question.

 

[StickyBandit]

What about air flow? or has that been mentioned?
Do the roots look ok. You should be able to tip the pots over and pop the plant out onto the palm of your hand with the stalk between your fingers

 

[*GROWHIGH*]

imo,...seedlings look elongated ..to much heat/moister , not enough fresh air ......i wouldn't say its your light...seedlings have to handle the sun upon germination ......seedlings often have the look yours do when left in a propagator for to long ....freakishly long stems which need to be supported ....hope you get to the bottom of it bro

 

[indoorpsychs]

imo,...seedlings look elongated ..to much heat/moister , not enough fresh air ......i wouldn't say its your light...seedlings have to handle the sun upon germination ......seedlings often have the look yours do when left in a propagator for to long ....freakishly long stems which need to be supported ....hope you get to the bottom of it bro

the seedlings are elongated because i thought my light was frying them.i have a lux meter and i start seedlings with 7000 lux.not the best to start seedlings with hps but i have done it and there was no problem.So when i started to see white growth i thought no way they have iron deficiency so young,my lux meter must be broken.but as you see from all the stretch my meter was fine.the heat and the moisture or airflow is not a problem.i have a proper ac unit and 2 hygro/thermometers in the tent.a 5 inch extraction fan extracting outdoors.so there are 3 parameters same to all those seedlings and 1 of them is the enviroment,2 lights and 3 water.everything i know about the enviroment is ok,temps humidity airflow.i dont own a VOC or Co2 meter so i dont know about that but never had problems with Co2 previous grows in different tent.For the water i have full analysis,it's 0.22 ec with 47 ppm calcium.

 

[indoorpsychs]

i don't know if this helps but all this time i have only one survivor.this girl is growing a little,very very slow, and then she is going full blown sick and then coming back growing slowly and looking partially healthy.She never grew side nodes before i toped her.This is something a have never seen,even in whole internet there are no plants with no side nodes 1 month old.and i don't meen small nodes not branching like when overwatered,i meen you couldn't see anything,every node just leaves.

 

[exploziv]

Could be a sign the conditions in the media are kinda bad, plant needs both certain micronutes and also hormones to achive that sideshoot growth, so any long/bad disruption of the nutrition can do stuff like that. Certainly not unexpected for how bad they look!

 

[FletchF.Fletch]

With your hps dimmed, are you using a lower wattage bulb? If you have a 600 w ballast operating at a lower setting your bulb choice should match your wattage selection or things won't ignite fully.

Looks like overwatering and too much nutes. Seeds can easily be started under HID lamps: 3-4 ft away for 400-600w, 6 ft distance for 1000w.

Good Luck, never give up!!