My seedlings keep dying & not growing

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Shneex0338

18
3
Hey guys,

So I went through a few communities & I'd like to ask here, too. I just love to get a few opinions here and there.

For whatever reason, I keep killing my seedlings / young veg plants. The germination always works wonderfully, they thrive in the first few days (5-10 days), but suddenly they always stop growing, and then become yellow & die soon.

Here are a few infos:

* Peat based substrate (BioBizz Light Mix), with perlite, worm castings, all that stuff. Also used Potting MIx, and also used BioBizz All Mix in a few attempts, always the same outcome.
* MarsHydro FC3000 light measuring around 250-350PPFD at plant height
* Temperatures around 70-77°F / Humidity 60-75% (Automated)
* 18/6 cycle
* BioBizz nutrient line, always just using Root Juice for seedlings, with some Bio Heaven here and there. All just organic stuff.
* PH after adding stimulants is at 6.3-6.5, with PPM at 400-450. PH Pen is Apera PH20, fully calibrated with 2 point calibration every few days.
* Water is dechlorinated and sits at room temperature of 70°F
* Exhaust fan works, slight negative pressure inside the tent
* Oscillating fan is moving air around, and creates a slight breeze around the plants
* Pots are tiny plastic pots with lots of holes at the bottom. I do have fabric pots, but they're too large right now (1 / 3 / 7 gallon fabric pots)
* Pots are always measured before transplanting the seed into them, to see the 100% dry weight. Then afterwards they're watered, and will get watered as soon as 85-90% of water-weight is gone.
* Myco cultures are always added into the soil as additive.

Yet they.. die. They all stop growing, and just yellow & die off. They don't fall down (damping off), they are sturdy, but they just stop their growth. Here are a few example pictures of my 2 last plants:


This is my current plant at 13 days now after germination. Growth has stopped as of the 6th day or so. Then the yellowing of new growth, and yellowing slightly creeping up the lower first leaves, too. Don't worry about the soil, it was watered a few seconds before I took this image, it looked fine afterwards.

My seedlings keep dying  not growing

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This was my older plant:

It was over 21 days old already, and stopped its growth around 14 days in. Then the whole plant became pale yellow-ish, and died, with the lower tips turning grey-ish brown.

My seedlings keep dying  not growing 2


I've heard several things already: Peat moss is bad, potting mix is bad, everything is bad. I honestly don't know what to use anymore, as everyone hates whatever I'm using and doing. My run-off PH is apparently bad at 7.2, yet others say runoff does literally not matter as long as the input water is PHed correctly. I use fully organic nutrients in "organic" soilless substrate, so I follow the rules of the manufacturer (BioBizz) with 6.3 PH, sometimes 0.1 or 0.2 more. I've heard that I shouldn't let my medium dry out, I've heard that I water too often, I've heard that they got a deficiency, yet the substrate has enough nutrients for 2-4 weeks, and my newest seedling is already yellowing after a few days, with almost no growth at all.

Is it the placement of my tent? It's in a slightly bigger empty storage room, in a corner, with one window a few feet away that I open sometimes. But I've seen grows done in tiny rooms with no aeration, which tells me that it can't be the cause. Is it my watering schedule? I did let them dry out almost fully, I tried everything, but they still stop growing for some reason.

I just.. don't know what to do anymore. I'm just absolutely confused. It's sad to open the tent every day, with the seedling literally looking like 5 days before, but it somehow isn't dead, it's just doing nothing and slowly yellowing. I LOVE these plants with all my heart, yet I see them die everytime because something is just severely wrong, yet I don't know what. I'm completely clueless and I need help.
 
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GoldenDragondnw

GoldenDragondnw

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Oh man I hate when my seedlings die too. I feel your pain. I'm not sure what your issue is but someone here will be able to help you grow em out strong. Good luck and happy growing always.
 
HerbalEdu

HerbalEdu

772
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i m with biobizz all mix and nutrients, i don't see anything wrong with your growing routine and i m a tad bit clueless as well, only difference i could see between you and me is from where the water is sourced from ...

i barely correct pH to7.0 before mixing the nuts and don't even monitor ec ...
 
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LoveGrowingIt

LoveGrowingIt

522
93
The soil looks like it might be too wet. That could be the cause of the yellowing leaves. So, I recommend letting it dry, but that's a problem in pots that don't allow gas exchange. It takes a long time for the soil to dry. I see you've tried different soil mixes. Keep in mind that seedlings shouldn't have nutrient-rich soil.

I suggest transplanting those seedlings to larger pots, maybe about one gallon. Use soil that is only slightly moist. That way, moisture from the existing soil will migrate to the new soil. That should help it dry sooner. If you have a soil moisture meter, keep it on the low end of the scale till the plant has new growth.
 
Imzzaudae

Imzzaudae

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There is nothing wrong with peat moss based mixes. Or the product line you are using.

You are drowning your seedlings with water. Seedlings need to be watered so the potting mix stays just moist not soaking wet. With the exemption of coco. When growing in coco you water more often.
Just stop watering them. Maybe an oz or 2 spread around the pot every other day. If it's not dry on top give it another day.
Give them a little what ever bio grow mix you have available as directed. And give them a few days. Keep in touch
 
LoveGrowingIt

LoveGrowingIt

522
93
I've heard several things already: Peat moss is bad, potting mix is bad, everything is bad. I honestly don't know what to use anymore, as everyone hates whatever I'm using and doing.
I doubt anyone here will hate what you're using and doing. Stay engaged. You'll find lots of good advice here. However, have you ever heard the old saying about too many cooks spoiling the stew? (I think that's how it goes.) So, it's helpful to determine your style of growing. For example, organic growers like me don't pay much attention to pH, but people who use synthetic nutrients do so (or should).

Root growth is the main thing a seedling does, so anything that impedes that growth will also impede the growth of the plant. So, I often look at the soil when there are problems with seedlings.

I don't use peat moss because it's commonly classified as a non-renewable resource.
 
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hoobastank_enthusiast

86
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everything is bad and we should all just stop what we're doing. really though there's nothing uncommon about what you're using
 
ArtfulCodger

ArtfulCodger

509
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I think your products are all fine. I don't have a definitive answer for you, but here are some things to consider. 1) 300 ppfd is a lot of light over a seedling. 2) Organic nutes take a while to become plant available. 3) When you say that you're recording "dry weight" and then drying back accordingly, is your dry weight measured with soil straight out of the bag, or after allowing the media to get truly bone dry? There is a huge difference in water content between soil in a bag and bone dry.

My guess is that at 300 ppfd, you're starting them with your foot on the accelerator. The nutes aren't keeping up, because they aren't sufficiently plant available yet. You might be further restricting the uptake by watering too often, if you're basing your drybacks on a dry weight that's not "dry." Here's what I'd try in your situation. I'd turn my light down to, say, 100 ppfd, and water to runoff only when the pots are very light. I'd be tempted to let them dry back the whole way to droop in the lowers, just once, to see where you are.

Just some ideas.
 
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Shneex0338

18
3
I think your products are all fine. I don't have a definitive answer for you, but here are some things to consider. 1) 300 ppfd is a lot of light over a seedling. 2) Organic nutes take a while to become plant available. 3) When you say that you're recording "dry weight" and then drying back accordingly, is your dry weight measured with soil straight out of the bag, or after allowing the media to get truly bone dry? There is a huge difference in water content between soil in a bag and bone dry.

My guess is that at 300 ppfd, you're starting them with your foot on the accelerator. The nutes aren't keeping up, because they aren't sufficiently plant available yet. You might be further restricting the uptake by watering too often, if you're basing your drybacks on a dry weight that's not "dry." Here's what I'd try in your situation. I'd turn my light down to, say, 100 ppfd, and water to runoff only when the pots are very light. I'd be tempted to let them dry back the whole way to droop in the lowers, just once, to see where you are.

Just some ideas.

Yeah I heard about organic nutrients taking their time to work, which often makes it harder to fight deficiencies too. Don't even know why I chose that path.

The weird thing is - My autoflower seedling is literally stretching to death at 300ppfd, it's all noodly and long and finally slowed down a bit.

By dry weight I really meant dry weight. Biobizz soil has small amounts of moisture fresh out the bag, but it's already dusty and crumbly. In this case I used a premade pot that has been sitting for some time, so it was really bone dry, literally dust. Then I activated it 36 hours beforehand with some water, and used it.

Ppfd starts usually at 200 for me, and then I raise it slowly over a few days to 300-350, until some true leaves come out, where I usually go for 400 for some time.

The watering, yeah, the god damn watering. I feel like this is just once again the case, I'm sure I just gave too much water at once, even though so many people say that it's not amount, but frequency, so I made sure that it's dry and then watered 1/3rd of the pots volume in water. But it does look like typical lockout from overwatering, I can't deny that
 
LoveGrowingIt

LoveGrowingIt

522
93
Organic nutes take a while to become plant available.
Sure, synthetic nutrients are fast, but that means nutrient toxicity is more likely and we talk about things like pH and flushing. That means synthetic nutrients are better for experienced growers. Organic growing, on the other hand, is more forgiving. Organic nutrients feed microorganisms (esp. mycorrhizae) that in turn feed the plants. It's a symbiotic relationship that regulates how much the plants are fed. Thus, how rapidly nutrients become available to the plants depends on the health of the microorganisms.
 
Imzzaudae

Imzzaudae

1,290
163
There is nothing wrong with peat moss based mixes. Or the product line you are using.

You are drowning your seedlings with water. Seedlings need to be watered so the potting mix stays just moist not soaking wet. With the exemption of coco. When growing in coco you water more often.
Just stop watering them. Maybe an oz or 2 spread around the pot every other day. If it's not dry on top give it another day.
Give them a little what ever bio grow mix you have available as directed. And give them a few days. Keep in touch
I went and download the nutrient schedule. I see that Biobizz has a microbe inoculate. You will need to use it or another microbe inoculate in order for the other mixes to work correctly!
 
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Shneex0338

18
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I'd just like to show my setup real quick, there's nothing wrong, or? Don't mind the huge pot with the tiny seedling, it's an auto and it seems to do just fine, besides the fact that it still became a noodle with 300+ PPFD. The one in the smaller fabric pot is my now transplanted slow seedling. I bit the bullet and turned it upside down, carefully took the pot off, to check the soil. Roots were okay, several big white roots around the sides, some coming out the bottom. But the soil was VERY moist to say the least, from top to bottom. I then transplanted it into pre-saturated BioBizz Light Mix (Just almost moist, maybe 10% water content to get it started, water won't come out if I squeeze it), in hopes that it'll suck up tons of the moisture from the smaller pot now, so it evens out with the substrate being able to breathe again. I have an emergency seed ready in the tiny pot with the plastic dome, but it's more of an experimental substrate with 60% Light Mix (It already has 30% perlite), and 40% extra perlite. Just insanely airy substrate, my gutfeeling told me it's the correct decision for me right now.

I went and download the nutrient schedule. I see that Biobizz has a microbe inoculate. You will need to use it or another microbe inoculate in order for the other mixes to work correctly!

I pretty much have every Biobizz product I could get my hands on, besides the microbes bottle. It's 70 bucks for 150ml, and that's.. a lot for me. Way too much to be honest. But I think it's only needed in normal soil, or? If I want to "revive" some noname product without any microbes in it. Otherwise I have every product of their line available.
 
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alpha.ganjaguy

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The watering, yeah, the god damn watering. I feel like this is just once again the case, I'm sure I just gave too much water at once, even though so many people say that it's not amount, but frequency, so I made sure that it's dry and then watered 1/3rd of the pots volume in water. But it does look like typical lockout from overwatering, I can't deny that
are you seeing a lot of water flow through and leak out the bottom? (your pots do have drainage holes right?)

I feel like 1/3 the pots volume is far too much water for a seedling.. mine go into 16oz (473ml approx) party cups and get maybe 5ml twice or three times a day until they have roots established and can handle a saturation type watering

I would expect them to damp off though before dying from nutrient issues related to overwatering
 
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Shneex0338

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are you seeing a lot of water flow through and leak out the bottom? (your pots do have drainage holes right?)

I feel like 1/3 the pots volume is far too much water for a seedling.. mine go into 16oz (473ml approx) party cups and get maybe 5ml twice or three times a day until they have roots established and can handle a saturation type watering

I would expect them to damp off though before dying from nutrient issues related to overwatering
Usually like 5% runoff, if at all. Yes, my pots have several drainage holes, I make sure there's more than enough to let water drain. Otherwise I'd really question my hobby here 😄

1/3rd of the pots volume is what people always told me for some reason. I did try the "dribble watering" technique like you, with 5ml in syringes around the plant in a circle and everything, the result was the bigger plant in the post above with a few nodes more, and it died later too, after being stunted for almost 10 days.

And yes, I usually expect leaves to droop, or for the seed to just straight up die with too much water, but they're all alive, sturdy, yet the leaves just yellow and die off until nothing's left.
 
Imzzaudae

Imzzaudae

1,290
163
Do you have a finished compost pile?
If so give your plants this and be very careful not to water to often.
When thy get larger give them this one. You can use muskie fish emulsion.
 
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Shneex0338

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Do you have a finished compost pile?
If so give your plants this and be very careful not to water to often.
When thy get larger give them this one. You can use muskie fish emulsion.
I have a ~30 or 40 year old garden compost pile that's still being used today, it's surely a few cubic feet of compost, maybe a ton? I already thought about using it in some way, but I feel like it'd be full of pests and fungi that may attack my indoor plants
 
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sinse

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If your a new grower I want you to try something next time you have a seedling. I want you to kill it by NOT watering. You'll find that days go by withough watering and your plant gets healthier and healthier. How can this be? Youll actually be surprised that the plant likes it's time with relatively dry soil.

I had seedling lightly watered go 5 days without water in little peat pellets and they were loving life. Bone dry and light as a feather when I watered them again. I think your over watering.
 
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Shneex0338

18
3
If your a new grower I want you to try something next time you have a seedling. I want you to kill it by NOT watering. You'll find that days go by withough watering and your plant gets healthier and healthier. How can this be? Youll actually be surprised that the plant likes it's time with relatively dry soil.

I had seedling lightly watered go 5 days without water in little peat pellets and they were loving life. Bone dry and light as a feather when I watered them again. I think your over watering.

That's the strange thing - I have tons of knowledge, but only technical knowledge. Practical is somehow the complete opposite. I only grew one plant in my lifetime, which was around 8 years ago, and it was a monster. I also had no real setup, it was all just homemade, I maybe spent around 20 or 30 bucks and came out with 7oz of yield with that one plant.

But now with LEDs, a good setup, a good tent, humidifier, everything, things just turned south. Nothing works anymore, I killed all my plants.

And.. Yeah. I think what you just said is my goal now. I'll just try the complete opposite & see if I can let them almost starve and ask for water. And that's when I'll finally water again. I think this was easier in my first grow, as I used a HPS lamp with tons of heat and light penetration, LEDs aren't as good in this case, so I feel like I may still water like back in the day, where the HPS literally burned out all the water in the soil in a short amount of time. Right now they still seem more than supplied with water, so it'll probably take another 3-4 days.
 
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sinse

72
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That's the strange thing - I have tons of knowledge, but only technical knowledge. Practical is somehow the complete opposite. I only grew one plant in my lifetime, which was around 8 years ago, and it was a monster. I also had no real setup, it was all just homemade, I maybe spent around 20 or 30 bucks and came out with 7oz of yield with that one plant.

But now with LEDs, a good setup, a good tent, humidifier, everything, things just turned south. Nothing works anymore, I killed all my plants.

And.. Yeah. I think what you just said is my goal now. I'll just try the complete opposite & see if I can let them almost starve and ask for water. And that's when I'll finally water again. I think this was easier in my first grow, as I used a HPS lamp with tons of heat and light penetration, LEDs aren't as good in this case, so I feel like I may still water like back in the day, where the HPS literally burned out all the water in the soil in a short amount of time. Right now they still seem more than supplied with water, so it'll probably take another 3-4 days.


Nice setup by the way. Watering is one of the things you can read about but you wont really understand until you've made a few mistakes. (learning the hard way). When your plant roots sit in too much watering without drying out, they get smothered and cant do their job. The light are on, the leaves are growing, but the nutrients arent making it to the plant. A lot of new growers try to fix this by adding more water, it then spirals out of control with a much higher risk of getting root rot or many other problems. Overly wet soil is one of the very worst things you can do...

Here is a 100 % fail safe way to approach watering on your next grow. Let your soil dry out and put it into your container. If you have a scale, weigh it dry. Now add water and weigh it at "wet weight". You can weigh daily to see how much water the plant is using and how much evaporates. You might be surprised how long it takes. There can be a lot more water in the soil than you think. Using weight will stop the guessing game and you will know for sure when its time to water. After a while, with experience, you'll be able to tell by simply holding the pot and feeling its weight....

I was so frustrated I decided to kill my plant. Shut the doors to my grow cabinet and left it alone without doing a thing for about a week. Thats how I learned. When I opened to door to check on my dead plant that I intentionally murdered, I was shocked and amazed to see the healthiest plant Ive grown yet.

Underwatering isnt good, but the plant will have clear signs when it needs water. The leaves will droop (not the same droop as over watering) and you can then give water ! Its pretty cool to see all of the drooping leaves bounce back to perfect health in a couple of hours after watering.
 

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