Seedlings keep dying! Please help!

[Ollylake]

Hi all!

I have completed two grows successfully but now I am running into issues now that I have begun an indoor grow.

I have a small 2x2 tent with 600W LED light. I am using my extractor fan to exchange the air every 3 minutes, drawing in fresh air outside my house. This keeps my temperature at around 22-25 celcius and humidity at around 50%-70%, but this is my second batch of seedlings to turn yellow, wilt and die! I initially had some issues with airflow and high temperatures which I have rectified, but now am unsure what I am doing wrong....

I think it could be overwatering, but it seems weird that it would be every plant in the tent! I have 14 seedlings and they’re all showing symptoms..

Any advice would be welcome, TYIA!

 

[ZeroTolerance]

Looks like you're plants are having nutrient issues due to pH problems.

Are you adjusting the pH of your water or using any nutrients?

 

[Ollylake]

Some better pictures

Looks like you're plants are having nutrient issues due to pH problems.

Are you adjusting the pH of your water or using any nutrients?

No I haven’t been adjusting, you really think that could be it? When I’ve been growing outdoors I have just watered from the hose...

 

[Nunyabiz]

What soil are they in?

 

[ZeroTolerance]

This is what my plants started looking like when my pH meter wasn't calibrated (water was about 7.0 pH)

Here's what they looked like two weeks later with water at 5.8 pH

Outdoor soils have thing in them that keep pH stable, so hose water is ok. In smaller containers and with potting soil those pH stabilizers are depleted quickly, so you need keep the pH adjusted.

You can get pH down liquid and pH test strips pretty cheap on amazon. You want a pH of 5.8-6.2 for coco coir / peat moss, and 6.3-6.5 for organic soils. People might have differing opinions on this, but in general around 6 is ok.

 

[Ollylake]

I actually have a ph pen and can just use vinegar as ph down. I’m going to try adjusting from now to see if that helps me. I’m hoping that it will!

 

[Tangie65]

What is the name of your dirt?
Have you fed any? Hope not. If not, I would guess over water too.
Unless that dirt is something like Miracle Grow?

 

[Ollylake]

What soil are they in?

What is the name of your dirt?
Have you fed any? Hope not. If not, I would guess over water too.
Unless that dirt is something like Miracle Grow?

I am using miracle grow potting mix, however I refuse to believe this is the cause as I have always used the same stuff and not had these issues before. I am not yet feeding them nutes.

I do think that overwatering was a lot of my issue, but not sure that’s all I can contribute it to.

I am going to try balancing my water to see if that helps.

 

[NewToTHC]

Any chance you have fungus gnats?

 

[013]

That soil looks kinda hot, appears that there is a lot of mulch in it. The soil compartment on those tray cups are pretty small too, I’m kinda partial to solo cups with holes for drainage and use a weaker seedling soil mix plus a fine mist spray bottle used sparingly.

read the bag on the miracle grow potting mix, some of their soil mixes contain added nutes to feed the plant for several weeks to months, typically the soil alone should be enough for seedlings but added nutes can make it too hot

definite signs of overwater too, tiny roots can’t breathe in saturated soil

 

[NuttyProfessor]

Miracle NOOOOOOOOOOoooooooo!!! .

wouldn't trust it with weed , if it has slow release pellets repot the lot asap and get better seedling mix soil
I don't think your little pods drain well , check the drainage holes as they get blocked with small particles in those Pods

 

[Ollylake]

Any chance you have fungus gnats?

I did have, but they are gone now. I threw out a whole load of plants because of it.

That soil looks kinda hot, appears that there is a lot of mulch in it. The soil compartment on those tray cups are pretty small too, I’m kinda partial to solo cups with holes for drainage and use a weaker seedling soil mix plus a fine mist spray bottle used sparingly.

read the bag on the miracle grow potting mix, some of their soil mixes contain added nutes to feed the plant for several weeks to months, typically the soil alone should be enough for seedlings but added nutes can make it too hot

definite signs of overwater too, tiny roots can’t breathe in saturated soil

I have always used the same soil up until now and not had these issues before, so I really don’t think it could be the soil.

Miracle NOOOOOOOOOOoooooooo!!! .

wouldn't trust it with weed , if it has slow release pellets repot the lot asap and get better seedling mix soil
I don't think your little pods drain well , check the drainage holes as they get blocked with small particles in those Pods

Pod drainage is fine, I have cut the holes out to aid in drainage. I think I need to adjust my watering practices tbh

 

[NuttyProfessor]

it looks like chucks of heavy peat this can become hydrophobic, water runs off doesn't wet proper ,

, take a sample out of a pod with no plant and see if the medium is hard , im thinking your roots cant get through , or get other pots or solo cups, they are saveable in the right medium and pot

 

[Ollylake]

it looks like chucks of heavy peat this can become hydrophobic, water runs off doesn't wet proper ,

, take a sample out of a pod with no plant and see if the medium is hard , im thinking your roots cant get through , or get other pots or solo cups, they are saveable in the right medium and pot

I’m going to try repotting, but the medium is not hard. The roots look good, and I’ve never had these issues before. I feel it’s something underlying that I’m missing..

 

[013]

The medium being hard is relative, it was soft but think it is now compressed by too much water / water too frequently. I would recommend switching over to solo cups (not clear or if you do use clear then use a dark cup to sleeve over it but make sure both cups have tons of drainage / air holes) then do the lift the cup method. Fill one cup with totally dry soil and use that as comparison weight - some folks weigh by hand others use digital kitchen scales. A dry cup of soil should be light as a feather. Use spray bottle mist for water sessions - young plants don’t need water every day. The more you start working on establishing wet dry cycle during veg the better off you will be.

When soil is totally dry she will send tiny roots out to search for water. A plant cannot grow above ground.... until the roots grow below ground to support and feed the plant. Young roots can’t breathe in continuously wet or wet compacted soil. If it’s not a water issue then check that MC soil bag for added nutes - usually says has nutrients or will feed for 3 months or something similar. The problem with time release nutes is young plants don’t need it. Even tho you have used this soil mix before you could have a hot bag or the pellets may have sunk to the layer you are filling your planter trays from.

I could be totally wrong here but hey just spitballing trying to get you over the hump! Hope something hits pay dirt...

 

[Ollylake]

The medium being hard is relative, it was soft but think it is now compressed by too much water / water too frequently. I would recommend switching over to solo cups (not clear or if you do use clear then use a dark cup to sleeve over it but make sure both cups have tons of drainage / air holes) then do the lift the cup method. Fill one cup with totally dry soil and use that as comparison weight - some folks weigh by hand others use digital kitchen scales. A dry cup of soil should be light as a feather. Use spray bottle mist for water sessions - young plants don’t need water every day. The more you start working on establishing wet dry cycle during veg the better off you will be.

When soil is totally dry she will send tiny roots out to search for water. A plant cannot grow above ground.... until the roots grow below ground to support and feed the plant. Young roots can’t breathe in continuously wet or wet compacted soil. If it’s not a water issue then check that MC soil bag for added nutes - usually says has nutrients or will feed for 3 months or something similar. The problem with time release nutes is young plants don’t need it. Even tho you have used this soil mix before you could have a hot bag or the pellets may have sunk to the layer you are filling your planter trays from.

I could be totally wrong here but hey just spitballing trying to get you over the hump! Hope something hits pay dirt...

That would make sense, I have been watering until runoff in these small pots and they’re taking a long time to dry out completely. Last time I used these pods I was watering with a spray bottle.

I’m pretty confident that soil is good so don’t feel the need to adjust that (specifically because I have another 10kg bag of the stuff unopened!).

I have definitely overwatered some, if not all of the seedlings.

Seems like a rookie move! I have started another load of seeds in the meantime while I figure out the issues with these... hopefully watering is the problem and as such I can fix easily...

 

[013]

I could fill cemeteries with the beans & seedlings I’ve slaughtered! It’s all good man - don’t sweat the petty stuff, it’s more fun to pet the sweaty stuff. Ha ha Anyway I hope you get her tuned up to your satisfaction!!

 

[Ollylake]

Thanks for the words of encouragement! It’s frustrating when things don’t go well lol!
I’m sure that I’ll get it dialled in eventually