When they are that size don't even bother thinking about the speed of growth. That seedling should be spending the next 2 weeks establishing roots not being driven to grow foliage. First come the roots, then the main plant structures and when those are all in place, the real growth spurt will...
Looks like no takers so I will have a go.
It looks to me like massive compounded shock on plants with tiny root systems developed.
For example:
Switching to the hydro method will be the first shock. Taking them out of the peat pots will no doubt damage roots.
84f is probably 7 degrees...
Switching the light cycle will definately stress the plants. Anything over 18 hours is a personal choice thing. The only time I would do it (during veg) is if I lived in a climate where it was so cold that the lights were better left on to help keep the room warm enough not to have to use extra...
Generally you do not see TMV kick into action until you switch to flowering. Plants become light sensitive, some leaves begin to distort and discolor, plants become heat sensitive and then the leaf drop begins around week 4-5.
This looks more like some other form of pathagen I am not sure...
Most of that looks like over feeding to me. Plus the leaves look like they are sensitive to something you are doing. Could be the heat or could be misting maybe?
The leaf roll can be normal for seedlings which can be heat senstive in their earlier stages, but when clones do that it is almost...
Seedlings have enough energy in them to get at least to the first set of real leaves. Do not feed them. Keep the rockwool moist but not soaking wet. Let the roots pop out the sides and bottom before transplanting/plugging them into larger rockwool cubes. Keep the light cycle constant and make...
You get that with some seedlings. It is a numbers game to get good seedlings.
A part from over watering and feeding them period which would have sent it into a head spin, the repotting at such a young age into what looks like adult potting mix will have damaged the root ball, all those little...
Its nutrient burn most definately. Use straight water for the next few feedings letting the pot dry out completely in between waterings. No nutrients and no additives. That only happens when plants have been over watered and over fed and in the meantime your plants will need time to recover from...
Its just nute burn which will right itself once you let the pot dry, then thoroughly water with straight water, then let it go dry again, and probably one more straight water. Time is on your side because you are growing in soil so no need to take drastic measures as one would when growing using...
Nothing to worry about. Watch the over watering. Just water for a couple of waterings and they will be fine.
Other than the slight burn the rest are to be expected from seedlings trying to find their way in the world.
Many new growers will see these signs and in their attempt to try and...
Generally the theory is about causing the cutting to want to grow roots rather than foliage. The chemicals that are released in the plant to repair the leaves are related to the same stimulants that will cause roots to grow out of the cut area on the stem.