pregrow help; just got my mango seeds in the mail dont wann kill em

hello i was just needing help on maybe sum sort of issue with my growbox setup or maybe even the soil. i planted seeds and the first time was growing good till i killed it (added beach sand cuzz i thought it help deter mites and stuff turns out salt in sand killed it), i decided to try again and germinated seeds planted in soil and saw the sprouts about to pop out they were right at the top then suddenly they died turning yellowish in color. wat could b causing this. i am using miracle grow moisture control its all i can afford at the time and read online by other users itll get the job done for beginners.

the soil itself maybe killing your babies. i use mostly MG products and have had this happen to a few plants due to the MG being to hot for young plants. instead of germinating in MG buy some seedling starter mix you can find this at Lowes or HD and itll say on the bag specifically for germinating, then once your babies sprout wait till they have the 2nd or 3rd set of leaves then transplant to the MG. this way your babies are pretty much gauranteed to not just fall over and die like that. also the seedling starter mix will hold moisture in pretty well so you wont have to water for a while and mess em up. hope this helps and good luck

I've only germinated in wet toilet paper from tap water, and jar. lol