Nute burn?

First grow and its ALL new. Started from seed (3 of 6 germinated: 2 Animal Cookies, 1 Northern Lights x Skunk). Photos taken 11 days after germination and 2 days following placement into hydro tub. Am using LED primary lighting with fluorescent supplement. Having a bit of trouble with temperature getting warm - up to 88F at times. Humidity is also a challenge due to a very dry environment.

Anyhow, within a few hours of starting in hydro, one A.C. started showing the brown spots. Then after two days, the NLxS started showing some burn on the tip of a couple leaves. The second A.C. is showing no apparent aberrations at all.

All three seem to be doing better now with the new leaf growth appearing normal. So I'm thinking the girls are recovering from their shock. But all three seem to be a bit on the small size (difficult to tell from pix).

What I'd like to know is: what caused the brown spots? I suspect nute shock, but it could be heat, or lack of moisture - or even a combo of all three. Any and all useful comments appreciated!

Poke

When did you start your nutes, as typically most will wait 2 weeks then use 1/4 strength
The heat is an issue, as 88 is getting near the upper limits, humidity is less important but if you are under 20% RH you may wish to consider a humidifier
Yes, lack of moisture could have caused that, did you let them dry out too long?
Dr. Jekyll

Posting pics taken under the LED are rather useless, as we can't judge the color of the leaves thus we can only speculate at best.
Mr, Hyde

Thanks DJ&MH!

Nutes started after 9 days from germination. And added at the "manufacturers recommended strength". So, that's likely the cause - too much, too soon.

Am learning as I go and hoping I don't fry these girls before getting things right.

Here's the same babies but minus the LED effect this time....

So now the question is: should the water be drained immediately and replaced w/ dilute nutes? Or wait a few days until the originally planned time to drain and renew the solution?

Poke

id do a flush on them
recommended amounts are for fully mature plants

but hey thats just me
id give them straight ph water for awhile