milocrab, you have got me all over the globe - Hong Kong, Asia, Australia! About your seedlings; the growing medium appears too heavy for a tiny mustard seed and you may have compounded the problem by your watering program. A seed needs to be in a moist environment to imbibe moisture in its own sweet time. If the medium is too wet the seed will rot. As the seed germinates it uses up its stored energy to produce a root and shoot. These are necessarily small, definitely immature and very sensitive to the environment. Application of fertilizer and exposure to (sun)light must be done carefully and gradually or the seedling can easily die. All of the leaves in the photographs show a nutritional problem; either a shortage of elements or else a problem with uptake if the elements are present. Overwatering can prevent uptake by displacing oxygen at root level The bleached areas on some leaves can be caused by sudden and perhaps extreme exposure to (sun)light; or damage due to the activity of the "blotch" (as opposed to the "serpentine") leafminer. 91ðF "even for one hour" to us can mean "for an entire hour?" to a seedling as it pulls on all of its meagre reserves to cope with this environmental stress. Allow me to reproduce from memory, a poem by Kate Brown from my kindergarten school days. "In the heart of a seed, buried deep, so deep; A dear little plant lay fast asleep. "Wake!" said the sunshine, "and creep to the light". "Wake!" said the voice of the raindrops bright. The little plant heard it And rose to see. What the wonderful Outside world might be." We had to mime as we recited and it is a pleasamt memory.

Even if you put rocks, still you have to have holes. That is a sure way of throwing out the extra water. Roots hurt and rot. Pinch the flowers this year. May be when your plant becomes large, you can leave them on the miniature tree. I live in Bowie, Maryland. We are in zone z7. That should give you an idea of our growing season. My flowers show up in April every year. By the time I get the ripe fruit, it is at the end of all good growing season. That's why I leave only a few flower bunches and pinch the rest of them. That way it also allows new growth. Indu

Regular potting mix can be problematic. Too wet and everything rots and mold develops. Too dry and cuttings eventually dry out. Perlite is usually the easiest thing to root in. Remember to put in drain holes and cover your cuttings. I've rooted rexes in straight potting mix (Miracle-Gro or Jungle Growth) with no water - the mix was already moist. Make sure you cover your cuttings. I prefer roasting pans with plastic clear lids. Poke holes in the bottom and fill with media (perlite, potting mix, combo, sand, gravel, Nature's Helper, etc) Some cuttings do fine by placing the leaf flat on the surface while others do better if you prop the leaf vertically and just have the stem inserted. Water rooting is best with the entire leaf instead of wedges but then I haven't tried wedges that much with water rooting. Also cover your cuttings even if you are doing it in water. I've had water rooted begonias in the same cup of water for up to 3 months inside a cookie jar for example. If let out in air you must monitor the conditions of your water and cutting daily. I suspect that bacteria and other germs are multiplying rapidly under normal conditions but don't know why it stays so clean when put into a terrarium like environment. The other thing is to select good size healthy leaves for best results. Time of year is another parameter. Summer and fall might be better for rexes. Anyway, try, try again and put a cover on your cuttings.

A few hours of LED light each day is clearly not enough replacement for plants (like echeverias) that crave full to shaded sunlight. Mine winter with grow lights up to 8-10 hours a day on a timer, even that is not enough to replace what natural sunlight provides. I set them about 2-3 inches from the actual light bulb, so if you can, adjust your lamp closer to the plants. If you are worried about overwatering, get a small fan to ventilate, and make sure the water doesn't sit in the bottom. Plants wise, your plants are looking fine. As crenda mentioned, flowers wilt and dry away. The most important things to keep watch are how the leaves grow. Healthy roots and leaves = healthy plants.