as already stated you need a high humidity environment cover them with whatever work and spray them with straight water every now and then also and just as important make sure the light is not to close the closer the light the more the plant needs water and as it cant supply enough as is any extra demands will def tip it over the edge . by the way that dont look like rockwool it looks like a jiffy pot and you leave them in it permenatly just bury it in the soil down so the top of the pot is flush with the top of the soil , remember until you got good roots u need high humidity, not sopping wet substrate just moist and not to much light at first ,