Getting concerned: white tips on the upper growth of my plants

[Toscano]

Hi everyone.

1st grow / indoors tent / day 25 of veg / 1 gallon medium-fertilised soil (soon to be transplanted to 3 gallon pots) / LED lights at 22inches or 60cm from the top (250W, full spectrum, ~330 µm/cm2/s at the moment) / max/min T: 70/79F or 22/26C / max/min RH: 51%/60%

When checking my girls this morning before coming to work, I noticed some white tips showing up on the upper growth leafs of my (photoperiodic) White Widows.

Please check the pictures.

Zoom 1

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Complete picture

I haven't included any nutrients/fertilisers yet in their feeding. We're about middle of week 3 of vegging.

The soil I'm using is sold as a "medium-fertilised soil" that supposedly has all the nutrients for a good two to three weeks (according to the manufacturer, please click here).

If the soil was over-fertilised too much for these plants, they probably would have burned when they were just seedlings.
So I'm not suspecting nutrient burn, but what the hell do I know?

If the soil is under-fertilised (suspect it isn't the case, given it's week 3 of veg and they say this soil has plenty nutrients for a few weeks), maybe this is a deficiency starting to show up.
Also not sold on that, but what the hell do I know?

The lights are around 22 inches / 60 cm, and the system is running in half power (250W). Plants aren't getting more than 350 µm/cm2/s max of PAR light, according to measurements.
But maybe that's even too much? What the hell do I know?

Maybe of importance, maybe not, but on the last two waterings (yesterday Wednesday evening, and the previous one on Monday evening) I only gave them a portion of water (around 600ml) that didn't create any runoff.
So, the last two waterings were around 600ml only, with no runoff at all.
Could this be a problem?
Too many nutrients locked down in the water bed/root zone?
Should I water them with more water and less frequency?

What would your guess be?

I'm not keen on the idea of adding everything under the sun to the mix and hope for the best, and probably create an even bigger nutrient problem in the end.

But... well... help! What the hell do I know, anyway?

Many thanks!

 

[mysticepipedon]

It looks like the slightest case of nute burn that can happen.

 

[Toscano]

It looks like the slightest case of nute burn that can happen.

But isn't it a bit weird given I've never added any nutrients yet (no nutes, solid or liquid, no add-ons, nothing)? I've just gave this plant ph'd water until now.

Also, do you think it looks like a "healthy green" to you?
I might be wrong, it can be a lighting effect, but I think I notice some pale green in between the veins.

Shouldn't these plants be a bit... idk... greener by now?

Thanks.

 

[Goodshit97]

But isn't it a bit weird given I've never added any nutrients yet (no nutes, solid or liquid, no add-ons, nothing)? I've just gave this plant ph'd water until now.

Also, do you think it looks like a "healthy green" to you?
I might be wrong, it can be a lighting effect, but I think I notice some pale green in between the veins.

Shouldn't these plants be a bit... idk... greener by now?

Thanks.

They doo look a little on the light green side, looks to be lacking some nitrogen. Might be time for some nutrients. Also you are using phd water in soil?

 

[Goodshit97]

They doo look a little on the light green side, looks to be lacking some nitrogen. Might be time for some nutrients. Also you are using phd water in soil?

Ignore that, i didnt read the initial posting fully through. Transplant those babies into those 3 gallon pots with fresh new soil.

 

[Toscano]

Ignore that, i didnt read the initial posting fully through. Transplant those babies into those 3 gallon pots with fresh new soil.

You're probably onto something regarding the nitrogen thing.
I'm mean, I'm a newbie on his first grow indoors, what the hell do I know.
But if there is "green matter" missing from those leaves, that means less chlorophyll, right? With less chlorophyl, less photosynthesis, less everything, problems creeping up.
Given it's week 3 of vegging, maybe it's a good time to start adding nutrients?

Find it hard to believe it's light burn, as I don't see the tips or leaves curling up. On the other hand, maybe that light is OK for good condition leafs, but probably a bit much for my plants whilst in this situation.

Well, I repot them next Saturday and we'll see how it goes from there.

Thanks.

 

[mysticepipedon]

N deficiencies don't show up at the top of the plant first, they first show up at the bottom.

Transplanting into a soil with some nourishment is definitely a good idea.