There are no coincidences.

Don't muck with your seedlings. If they're in soil let them get true leaves out before you even think about feeding.

I trust the rocks are mulch, not the rooting medium?

Thank you for the reply. You are right it is mulch. Before I had problems of fungus gnats so just I covered it as a prevention of larvae of gnats :). On the other hand some of the young plant's the seed-cover are stuck on the new leaves long time so I think this rock can solve the problems.
I had experience of peat moss for germination and now I have changed to mixed soil such as pine-bark,perlite, vermiculite and peat moss, a kind of experiment I have been doing. My mixed soil is not much effective on germination. I checked the roots of some young plants and found the soil easily broke and left the roots are naked. Some problems are when I transferred the seeds from the paper towel germination to the small containers with the mixed soil some of the seeds got stress and died before the first leaves are not yet formed completely. I have already lost about 3/4 germinated seeds. So I applied ST 50 in 1 to see the improvement. I am more confidence with the peat moss for germination than the mixed soil I have made. Now I back to peat moss for germination. I cannot control the moisture very well with the new mixed soil, it dries so fast and a little bit more water it wets the soil. I am a bit early to experiment this mixed soil for the young plants I consider myself.

Like this picture some of my young plants started growing and and died with the mixed soil. Some of them died earlier, I will upload the pictures.

This seeds was a healthy germinated seeds with a long radicle, now I do not see any growth and the color of the radicle is yellowish now, I think it is already died.

Same condition.

That soil looks extremely wet. Unless you just watered, I would say that overwatering is one of your biggest problems. Seems overwatering is a problem for many pepper growers. Beginners clearly have the hardest time with overwatering. Not only does the saturated looking soil say "overwatering" but the fungus gnat problem does too. They thrive on wet soil. If you want to control fungus gnats, water with a 5 to 1 solution of water to 3% Peroxide. It will kill the larvae and break the breeding cyle. However, you have to do it for a couple weeks at least to ensure you truly do break the cycle. It will not harm the seedlings or mature plants. After you break the breeding cycle, you can continue to water with a weaker solution to prevent future infestations....probably about half strength.

PS: your "mulch" is probably holding in a lot of moisture and not allowing the soil to really dry out.
Bruce

Thank you for the advice.

I found these two seeds almost dried. When I moved from the paper towel to the small containers I did not cover the whole seeds, I exposed part of the seeds and I think it will be helpful when it grows. I have few questions for the germination and repotting:

1. Should I cover the germinated seeds with a thin layer of soil?
2. Should I keep the soil contact with the roots, tight or very lose?

Honestly requesting your helps.

Bruce is right.
Stone mulch is probably not allowing the soil to dry out quickly enough.
Edymnion is also correct in that seedlings don't need fertilization until
they at least have a true set of leaves maturing.

Josh

What he said, they said. :) Have you considered trying the baggie method of germinatingthe seeds? Peppers are particuarly well suited to it, since some of them have such long germination periods. It's easier to keep them properly moist without going too far towards wet, and easy to monitor their progress. Or are you already using it? I'm not quite clear on that because you mention a paper towel, but then I can't quite figure how the seeds get stressed between paper towel and pot.

As for proper soil moisture, think of peerfectly moist chocolate cake, rather than wet, sticky batter (or the dried out last piece that no one quite wants to eat). That's what you want to maintain. Yes, plant the seeds under a layer of soil, or at least poke a little hole and get it down in a little way. Sitting right on top always seems to lead to tippy seedlings which don't make it. As for soil contact, it's a Goldilocks thing, neither tight nor loose, but in between will be "just right". Cheers!

Thank you all for all these information. I removed the stone mulch.

The germinated seeds from the paper towel I transferred it to the small containers. When I put the new germinated seeds to the containers I partially exposed the part of the seeds. I think the soil contact with the germinated seeds were also very lose. So it will be one one the reasons the germinated seeds got dry/stress I think.The pictures were taken after watering. Now I made some correction, all my new germinated seeds are under a thin layer of peat moss soil. For the mulch I covered with dry coco coil, it sucks the excess water from the soil too and it is easy to replace with dry one again. I use wick for self watering, the containers I use are transparent plastic glass. The soil contact with the germinated seeds are also not very lose like before, there is no gap between the germinated seeds and the soil. The picture is the result. Thank you all for helping me.

I wouldn't water by wick from the bottom.
The plant is no where near large enough to draw so much moisture from the mix.
Peat moss and Coco fiber both hold excessive amounts of moisture and are very slow
to dry back out. Once dry, they tend to be hydrophobic. In addition, Coco has less "loft"
than peat moss, which is detrimental to structure/aeration in the mix.

Josh

I dunno, my preferred starting method these days is a bottom wick coir setup. Once you get the initial wetting done, the natural tenancy of the coir to pull up water keeps it at just the right moisture level without being soggy.

One of those cheap tray kits from walmart or ACE works great for it.

Yes, the plants are very small and not enough long roots to get water from the bottom, but from my experience the wick suck the water so fast. I use long wick and put in the center of the container. The containers are transparent and I am able to see the soil condition.

The small containers with the wicks I use dry so fast. It is an experiment, I have to monitor how fast the soil dry and how many ml of water is it. The picture is after I watered the plant about 20 minutes ago and the glass is just for the photo-taking. I hope you can see the way soil absorb the water. If I watered too much the color of the whole coco coir is changed (means absorbed the water). According to the wetness of the soil I changed coco coir with dry one time to time.

For 49 cells propagator without heating is available, it cost about $25.00 without shipping charge. It should be very nice for the beginner like me.

I have some kinds of passion of using available materials to serve the purpose:). Such type of practice must be done after I had some experiences. I have been learning container gardening here. As much as I can I have read posts available in the forum. I missed a lot of basic information that's already available here too. More problems means more learning for me :).

Thank you all for your advice and opinions.

A bit clearer picture.

This Plantstart Pluggbox is cost about $25.00. I like it, it is very nice. When the plants are ready for repotting I do not need to squeeze the cell to remove the plants just like I do with my small containers. I do not need to monitor the soil moisture frequently. Probably some of you already have the experience with this Pluggbox.