Support - yellowing from the center

I have a seedling with yellow color towards the center. Ends of the leaves are green. Otherwise growing well. My other seedlings are nice green everywhere. No nutrients added yet, just fresh organic soil.
Center yellow indicates what?

Strain = Northern Lights from seed

Soil in 5 gallon buckets = organic potting soil, worm casings, spagnum peat moss, perlite, sand, lime,

System = Indoor tent, soil based grow.

PH = 7 on cheap soil probe

nutrients = No nutrients added yet, just organic soil.

Indoor tent 3x4

Lights = Sun Systems 315W LEC 18 inches above seedlings. 18/6 cycle.

Temps; Day 75F, Nights 65F

Humidity; = not bad (California wet winter)

Ventilation = interior fan, no ducts

AC, = None

Co2; = No

Hi @Budlite

is this the only plant your are growing right now? If you are growing others, how do they look?

What brand of soil you using?

7 ph of your water is a touch too high.

Do you have plenty of drain holes in that bucket? how often do you water, to what quantity?

Also I think your light is a tad too close? But I don’t know LEC lights, so I will defer on that one @Niala @Matthew420

I know, a lot of questions, but the answer could be in there somewhere!

I would refer to the user manual for the lights. Seems a bit close but I’m not familiar with that light.

Your light range is about perfect I am upgrading to same lights and have spent countless hours reading up on them at 18" you wouldn’t want to get much closer than that.
ph is slightly high but mostly it’s just a hungry girl

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If you are curious I believe I posted some stats and info on LEC (CMH) lights in my from the ground up thread as well it is discussed few times in some other threads I can’t recall atm

The soil probes will give you no where near an accurate reading, get yourself a cheap ph pen from amazon to test the ph of what your putting in, then test whats coming out in your runoff to give an accurate reading of whats going on in that root zone.


This is my only Northern Lights seedling. I have some other Blue Dream that are about the same size, but better green color. The soil is a mix of organic potting soil, worm casings, peat moss, sand, lime. The soil is light weight, and drains well. I had expected the natural nutrients to last into veg growth stage. I know yellow tips may mean N deficiency, but I have yellow in the center, with green tips. My crappy soil probe reads between 6 and 7, slightly different in different spots. Light at leaf level feels warm but not hot, recommendations on these 315 Watt lights is 2 foot above plants, I spray the leaves every day.

Looking for a recommendation to start feeding, but it seems early.

You should listen to @BondPacker your pH is probably nowhere near what you think it is, get a pen type pH meter

Prove it to yourself, put probe in vinegar which has a pH of 2.0 - 2.2 and see what your probe reads


If it yellows from the inside out its a sulfur deficiency but I agree ph pen 90% of problems are ph related

I just ordered a pH pen (HM 80) and will probably start feeding veg nutrients.

I’m using FFOF, FFHF and a generic potting soil. I am in week 5 and other than some super thrive when I transplanted I haven’t given her anything. I wouldn’t rush into the nutes until you sort out your current issue.

Get that water ph’d and then if you decide to start nutes bring them in slow at 25% strength and then pH you water after you add the nutrients. Nutrients will lower the ph of your water, in most cases.