From a fellow grower: seeds germinate then seem to take off but die. We used the plant starter dirt called Chicken Poo we got from Menards. I was watering every couple days as the soil would dry out. The start turning yellow then die
Post a pic of the soil bag that has the nutrients listed Growmie. Several variables required to get through the seedling stage…mainly a cannabis friendly medium, temps around 74-85, RH around 65-75% and the lighting fixture set for this growth stage 
Probably related to watering practices.
For the first 1-2 weeks after a seed has germinated, the seedling does not get its nutrients from the soil - it pulls it from the moisture in the air (which is why high RH during the initial stages of growth cycle is so critical) and through photosynthesis. Both OGIncognito and Dexterado are spot on.
So the most critical areas of focus are: temps (as mentioned above), RH and the light source (proper distance and DLI are key).
As for the soil - do not water. Once or twice a day, use a spray bottle to mist the surface and keep it damp - not soaked - damp.
Also, early morning (or prior to lights on), lightly mist your seedlings with a foliar spray (I used a mixture of water + liquid seaweed). You’ll hear people say not to do it but folks I talked to at University of Colorado Department of Ecology and Evolutionary Biology say otherwise.
Plants take in a tremendous amount of nutrients through their leaves - especially seedlings as mentioned above (it’s basic plant biology). So this is a great way to boost the health of your seedlings (and your plants through veg/early flower).
Avoid doing it close to lights out, since your cannabis plants respire during dark hours, releasing excess oxygen and synthesizing glucose. They don’t necessarily ‘feed’ at night and overly damp leaves can hinder this natural process (which is why its also important to insure your RH is lower during light-out).
Also, the liquid seaweed has many beneficial properties for plant/soil health, including pest control (to a certain degree).
As the root system starts to take hold and the plant starts to take in nutrition from the soil, slowly transition from misting your seedling to lightly watering the soil around your plant. If in doubt, always err on the side of caution and underwater.
That should get you past the initial germination and into the Veg stage with healthy seedlings.