Yellowing seedlings

My seedlings are starting to turn yellow and curl down. I’m not giving no nutrients, my led light is a vipar spectra 300w is at about 37 in above, and my soil is fox farm. Temperatures are between 75 and 81 degrees but my humidity is a problem as it’s below 20 percent so I put sandwich bags over them to act as a humidity dome and poked holes in them. I don’t know what I’m doing wrong and my tips are also on 1 of em are turning brown.

Leaf clawing is often a sign of overfert. I believe many people cut the FF with 30%+ Perlite?

But IMHO they look underfed, and not enough soil. Usually yellowing from the bottom up, is a sign of Nitrogen Deficiency. But if they aren't being fed, I'm sure they have an overall deficiency, and will be quickly remedied, if you give them more soil, and food.

Lights need to be closer. They also look dry ????

Always give as much soil possible, and start feeding as soon as you have the 1st serrated leaves, unless you have a hot soil mix. I don't know what you have so I cant be specific, and sometimes 1 thing, can mimmick another. I usually start feeding them 20% solution, as soon as they pop out of the ground. And I feed every watering. But watch, and maybe skip on the 3rd, but usually I don't have to. Just depends on the strain,, and temp can have a big influence. Cooler temp, require LESS fert.

I dont use LED but I believe 18 inches above the top is safe?? Others can chime in that have more experience wIth LED. I have 0, but I do have 40+ years with HID.

Id up pot, and water/feed with a 20% strength fert, and don't soak them until theyre drenched. Just a medium watering, no runoff at this point as the roots aren't big enough, and will stay wet to long If in a 1 gal, or more pot.. More as you get root growth. I like to use a moisture meter, and let them get to Low Moist, and NEVER DRY, and never sopping wet, until they have a huge root system vs pot size.

I myself like to use 32oz cups and stuff them with soil/Promix BX . 32oz gives a good root system for seedlings, and not having to disturb them for a while..

How often are you watering? Looks like over watering and poor drainage. I also like to fill the cups all the way with soil, gives roots more room.

IMO I would lower the light to 20in, let soil dry out a bit then transplant into larger pots. Cut the soil with lots of perlite. Shouldn't need nutes as long as you keep up potting.

Get them out of the cups. Actually fill the cups with soil then replant. They need something bigger if you have it.

It could be over water if those cups don't have holes. If they do have holes it is chronic under watering.

dubekoms said:

How often are you watering? Looks like over watering and poor drainage. I also like to fill the cups all the way with soil, gives roots more room.

IMO I would lower the light to 20in, let soil dry out a bit then transplant into larger pots. Cut the soil with lots of perlite. Shouldn't need nutes as long as you keep up potting.

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I’m watering whenever the top soil seems a bit dry, the cups do have a bunch of hole on the bottoms and my soil is cut with perlite.
I’ll probably lower the lights and up pot but I feel like that would dry the plants out even more.

whitebb2727 said:

Get them out of the cups. Actually fill the cups with soil then replant. They need something bigger if you have it.

It could be over water if those cups don't have holes. If they do have holes it is chronic under watering.

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I was trying to wait until the plants had a nice rootball in the cups before i transplant. I’m gonna be going into a 5 gallon fabric pot( final resting place), you think I should transplant now.
I’m not sure if I’m over or under watering. The plants aren’t drooping they look more like a curl and the tips are on a one of them are brown when the others are just a light green.

Here’s some more pics

There's enough food in ff soil for the 1st month.u don't have to add nutes.i would work on your temps and humidity.and more soil also.led company's are all different. Each light has it's own specifications. Look your light up online or customer support.i use a viparspectra 600 and for the 1st 3 weeks as a seedling I have to keep mine at least 36 inches away.then I start dropping it in veg.if they're not getting good light they wl stretch for it.and then u will know.18 inches is way too close for a seedlng.when I have my temps and rh in check I don't see many problems.dont over and under water.anf ph water.those are my some guidelines and it works for me.i also use microbes and it keeps em healthy.good luck

I run 1000w HID/Hortilux Superbulb at 24 inches for seedlings, with no problems. But 20% humidity is way to low.

• VIPARSPECTRA Reflector Series V300 LED Grow Light is scientifically engineered to keep the balance of the PAR Output and Coverage.
• The secret to the VIPARSPECTRA LED success is the optimal full spectrum which provides plants Veg and Flower all stages with everything they desire in the natural sunlight.
• Compares to traditional 250 watt HPS/MH while consuming only 136 watts! Perfect for a 2x2’ vegetative coverage at 24” while 1.5x1.5’ flowering coverage at 18”.
• Advanced high speed quiet fans and upgraded aluminum cooling heat sinks are easy for heat dissipation.
• 3 years local warranty plus 30 days satisfaction or return guarantee.

• 
  Its only 136w in reality, and it also says it can be run at 18 inches and cover 1.5 x 1.5.

• 
  

Clementscr said:

There's enough food in ff soil for the 1st month.u don't have to add nutes.i would work on your temps and humidity.and more soil also.led company's are all different. Each light has it's own specifications. Look your light up online or customer support.i use a viparspectra 600 and for the 1st 3 weeks as a seedling I have to keep mine at least 36 inches away.then I start dropping it in veg.if they're not getting good light they wl stretch for it.and then u will know.18 inches is way too close for a seedlng.when I have my temps and rh in check I don't see many problems.dont over and under water.anf ph water.those are my some guidelines and it works for me.i also use microbes and it keeps em healthy.good luck

Click to expand...

Yeah I dropped my light to 30 in but my plants aren’t stretching so I don’t think it’s the light. I’ve been using the liquid ph tester that comes with the up and down but going to get the digital reader so I can know the exact ph rather than base it off a color. The only thing I can think of is the humidity. The tent is running at 20-25 percent. I have no way of fixing it until I transplant where the abundance of wet soil would fix the issue but for now I just have little sandwhich baggies over them, and i just added more soil. I’m not gonna water for another day or so to see how they react and go from there.

LighterLit said:

I was trying to wait until the plants had a nice rootball in the cups before i transplant. I’m gonna be going into a 5 gallon fabric pot( final resting place), you think I should transplant now.
I’m not sure if I’m over or under watering. The plants aren’t drooping they look more like a curl and the tips are on a one of them are brown when the others are just a light green.

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You don't have enough soil. Just put them in the 5 gallon and don't do anything for a week to ten days.

LighterLit said:

Yeah I dropped my light to 30 in but my plants aren’t stretching so I don’t think it’s the light. I’ve been using the liquid ph tester that comes with the up and down but going to get the digital reader so I can know the exact ph rather than base it off a color. The only thing I can think of is the humidity. The tent is running at 20-25 percent. I have no way of fixing it until I transplant where the abundance of wet soil would fix the issue but for now I just have little sandwhich baggies over them, and i just added more soil. I’m not gonna water for another day or so to see how they react and go from there.

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That's the problem. 20% is way too low. Get it up. The cups are drying out too fast.

20% rh is manageable when you've got 5 gal of substrate to hold onto water. I personally like the long veg, so I use 15-17 gal fabric pots, used to use 10gal but I thought they were still too small (my first grow was in 1 gal recycled plastic pots with dirt dug from the back yard and no perlite...lol). But I'm with everyone else, pot up to whatever you plan on finishing in.

Your issue is likely due to the fact that your plants are so small/young, without a root system capable of taking in the amount of water required to maintain osmotic pressure. Most everyone is fighting the same battle right now, being winter time the air in our grow rooms is staying too dry. I tried to keep up with mine, but I was refilling my shitty little dehumidifier twice a day and still not breaking 30%rh. My situation resolved itself once the seedlings began developing an extensive root system capable of keeping up with this dry ass air.

dtl420 said:

20% rh is manageable when you've got 5 gal of substrate to hold onto water. I personally like the long veg, so I use 15-17 gal fabric pots, used to use 10gal but I thought they were still too small (my first grow was in 1 gal recycled plastic pots with dirt dug from the back yard and no perlite...lol). But I'm with everyone else, pot up to whatever you plan on finishing in.

Your issue is likely due to the fact that your plants are so small/young, without a root system capable of taking in the amount of water required to maintain osmotic pressure. Most everyone is fighting the same battle right now, being winter time the air in our grow rooms is staying too dry. I tried to keep up with mine, but I was refilling my shitty little dehumidifier twice a day and still not breaking 30%rh. My situation resolved itself once the seedlings began developing an extensive root system capable of keeping up with this dry ass air.

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Yeah I transplanted them yesterday into there final resting place and gave them a little water I’m at 35% right now but it’s till dry in there. I added the co2 bag to hopefully help them cope with the light a littler better and there conditions but like you said I probably have to just wait until there is a good root ball. When i transplanted the roots were there but not how I wanted them to be so hopefully things get better. Thanks, all of you, for the feedback.