Dying seedling - Can't figure what's going on

[OldBullLee]

Hello to all growers,
I made my own little setup roughly three weeks ago, starting with seeds. I have three plants: Moonshine's Ghost Train, Pineapple Kush, and Hawaiian Snow. They're growing under a 125w CFL, in soil (biobizz light-mix). I water sparingly as they're still young. The only problem is, two of my plants are just fine (well, the Moonshine really thrives, and the Pineapple follows straight after), but the Hawaiian Snow is slowly dying, leaves are yellowing starting from the tips, and curling on themselves...I have to clarify, the seedling seemed weak since the beginning compared to the others, but it seemed relatively healthy until this point where the leaves started to wilt then to yellow...I can't reach a correct diagnosis, as I have very little experience in this matter. Any help or advice would be greatly appreciated!
Thanks in advance

 

[mypassion]

Maybe it needs more feed... what are you feeding and how much?

 

[OldBullLee]

I've started feeding them two days ago, with a half-dose of biobizz fish-mix in the morning, and sprayed them with a quarter dose in the evening. It only got worse since (it has clearly stopped growing), whereas the two others are just fine. Maybe this one has specific needs, or maybe it was just weak from the beginning

 

[Dan Ultra]

Seedlings should not need nutrients for weeks. They have everything they need in their cotyledons and the surrounding soil. If the soil was too hot, or you fed too much, or your pH is off then you might have locked it out and now it can't get anything.

Even the new growth is sporadic and twisty, which leaves me to believe there is probably a pH issue. Check pH before watering and make sure you are in a proper range for your medium

 

[OldBullLee]

Thanks for your answer. I only started to feed two days ago, less than recommended, and the two other plants seemed big and healthy enough, and they still are. They're at least five times the size of this one! The HS already had problems, and looked this way since it sprouted, only the leaves started to yellow from the tip one week ago I think. So, I figured I had nothing to lose trying to feed it too, as I thought it could be some kind of deficiency. I'll definitely get a tester and check the PH to clear this up, but believe me, the two others are as well as they could be and seem to have no problem, and I treated all three exactly the same way.

 

[AKgramma]

Some seedlings just have poor genetics. Like all living things, the strong survive and the weak perish. This early in the grow, I would not waste your time on a dying seedling. Put your efforts on those that have a good chance on surviving to harvest.

 

[OldBullLee]

Well, it's almost dead now anyway, so that's what I'll do. At least the others seem very promising!
Thanks for your answers, and happy growing

 

[Emilya Green]

ouch... please let me clarify some ideas here.

First, seedlings don't need nutrients. They come equipped with a suitcase of supplies and can easily get through the first week or so without anything, even soil, although we would never recommend going that far. Since they have no need of getting nutrients from their surrounding at first, pH is also not a factor. The pH of the seed pod and the cotyledons all match the rest of the system at 6.5 pH and everything should be fine in that department. Also, since they came with everything they need for a while, this also can't be a nutrient deficiency.

Egads! What could it be?

My guess is watering too often. These are weeds. They need to dry out, all the way to the bottom. Every time. If you are watering every day, or even every other day, you are most likely watering too often and drowning your young plants. The stronger plants were able to develop more of a root system and may be surviving the flood waters better... but everyone will most likely benefit from realizing that you don't need to water so often.

Now, I know you said you water sparingly.... but your picture showed a plant that had been sprayed with water. I am not sure that you and I will agree on the definition of sparingly, when it comes to a weed.

When you water, water with gusto. Fill up that container with so much water that it cant hold another drop without it coming out of the bottom. Saturate that soil. This is not sparingly. This is watering your soil properly.

After you do this however, then wait. Wait 2, 3, 5... however many days it takes for your plant to use all of that water. Use the lift method to determine if this has happened. Lift up your container. Can you feel ANY water weight? If so, wait another day to water. I am sure that if you start treating this weed like a weed, and not an honored constantly watered guest in your vegetable garden, you will start having a lot better luck with your seedlings. Good luck!

 

[OldBullLee]

Well, thanks to all for your answers. I repotted it in a small pot and removed the dead leaves, even though I think it won't come back. I must particularly thank Emilya; I followed the link on your signature where you explain how to water properly, and you enlightened me on this matter. I'm sure the two other will be just right now; moreover, they're getting taller faster than I realize.
Thanks again for your help!