16 d old seedling tips look "burnt", leaves yellowing


First time grower, I have AK-47 seedlings that are now 16 days old in rock-wool cubes. Leaf tips looking dried out and leaves generally yellowing. No fertilizer, pH 6.0 water. T5 fluorescent tube 2" above the plants and oscillating fan. Terrified of over-watering, I may have been under-watering. Now dip cubes in water for a couple of secs in the am and spray a couple of time in the pm.

. Suggestions? Thanks! .


If you haven’t feed nutes then that’s not nute burn, I do see nitrogen deficiency , see they need nutes. The burnt ends maybe signs of a calmag issue but I not sure.


Looks like ph is to low for young plants up ph to 6.5 see if that helps. Also their ready for dirt or whatever medium your using.


@Hogfather im not sure either. I have an AK47 that i started on sept 7th as a seed. Soaked in water overnight, then str8 into FFOF soil. Once sprouted, cover with dome as they need high humidity at this point. Dont water. Spray leaves and inside of domes. Here is a pic of my 10day old, she is beginning her 3rd set of leaves in the middle there…

Maybe it is your rockwool or maybe its lack of humidity but i cant be too sure as im a newb myself


Rock wool has no nutes, so I’m sure they need some. But as to why your plants in ocean forest are looking the same way @VelcroThumb my only advice would be that oc is very strong but can start seeds. With you just spraying them you may have a lock out causing nitrogen deficiency. Just a theory …


@Wishingilivedina420state IMO i dont think our plants look the same at all. I was more so posting a pic for comparison. The leaves on his look very yellow and started to crisp


Ok then I’m sorry


What are you going to be growing in after the rockwool? Are the roots coming out of the bottom of the cube? If so it is time to transplant!

You need to post a support ticket asap! @Hogfather

COPY/PASTE: This “Support Ticket” into your forum post.
Answer these simple questions the best you can.
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Strain; Type, Bag seed, ILGM… name of strain:

How many plants:

Age from Sprout and Flower:

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How often do you water and how do you determine when to do so?

PH of water and runoff or solution in reservoir:

What is strength of nutrient mix? EC, or TDS:

Indoor or Outdoor:

Light system, size and height from plants:

Temps; Day, Night:

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@Wishingilivedina420state no worries! It could be the lighting or angle of the pix!


True , but your pics show a lot of yellow.


You are right VelcroThumb, your plant looks great compared to mine. I started in dome and ~80% humidity, but the light was too far away and lost 2 seedlings to weak stretch stems. Also, I was paranoid it was too humid, so took off the dome, moved light 2" away, 60% humidity, and now they are stunted, crisping and yellowing.


Support ticket info:


I think they need to be transplanted asap! @Hogfather

When they go into the FFOF the pH will need to be 6.5.

I would keep them under the t5 but I would dome them up as soon as you transplant and keep them domed up for 3-5 days.


OK, thanks, I should just put the rock wool cubes direct into the soil I assume.


yes, they are in that rockwool for life. I’m betting they will pull through but they are in pretty tough shape.


Many thanks. I’ll let you know how it turns out.


yes do and ask questions about anything as you go. It’s much easier to explain something in advance than it is to fix it after the fact.

I would recommend a minimum of a 5 gallon pot. AK47 can get pretty big! It’s good medicine too! I have some jarred up from a previous grow and it’s a great afternoon, after dinner med!

tag like @Hogfather @bob31 and it notifies us that you are updating or asking a question!


I’ve put them in 3" pots with FFOF for now, back in the dome, and sprayed inside dome to get humidity up with pH 6.5 water. The grow room has 10g pots with MH lamp for the veg stage, hoping we get there. Or maybe I should move there immediately, but my instinct is to hope for recovery under the dome.


@Hogfather i did the same thing, except i was watering. @bob31 caught me and corrected me. Try to put them in domes and just spray. Let rockwool dry out and continue to mist leaves and domes. High humidity seems to be key. It was a night and day difference after that did that. I will go back and tag you in a previous post where my strawberry kush was yellowing and since i domed them, it has stopped!


@Hogfather rock wool needs to be keeped moist or your roots will start to die off
Keep cubes moist and see if they recover