You are getting plenty of suggestions. It is amazing how many ways there is to do something so simple. In lots of cases it is just shitty seeds. Once someone has problems they reinvent the simplest part of growing. Now there are lots of people doing way more than they need to. Water, paper towel, and seeds is all that is needed.
People say add warmth. The light should be taking care of that. If not the area you are trying to germinate in is way too cold or hot. The warmth from the light gives the seedling directions of which way to grow. They can't see the light. It is the warmth they grow too. With no light and warmth from below seedlings as in warming pads. A seedling can grow the wrong way.
Well made seeds can pop in less then a day. Very few take longer than a few days. If your basic water, paper towel, and a seed are not working. It is probably the seeds and not you.
Seeds that pop a tail and don't grow through the soil. Either went the wrong way. Or in most cases it is the seed. I have had this happen before also. What I found was the part of the seed where the leaves should be had dried and stuck to the shell of the seed. Had a great looking plump white tail with nothing on top. I have also had seeds come up with no head on them at all. If there are no leaves they won't grow. Never knew what was happened till I found a seed with the dried part and a great tail. I don't know where in the seed making process things failed but they did. I have never had this problem with my own seeds. Age may be the problem but is doubtful. I have seeds from 1998 that still pop.
