Its been 4 days in soil germ method using coco, an...

I wouldn't worry just yet, half an inch is quite deep, you only really want to go twice as deep as the seed is in size or about quarter inch maximum. As long as you are giving enough water to make sure that water reaches down to an inch and a half deep and not just wet the surface layer, your seed should till sprout. It can take up to 5-8 days for a seedling to emerge, so don't give up just yet. The fact it is so deep may delay its emergence for 24-36 hours over "normal" time. It can help to keep the surface layer from drying out and for this I have used, at times, a small square (approx 4 x 4 inches) of "shade cloth" to lay on top of where the seed is buried, but you have to check underneath the shade cloth at least twice a day and remove it as soon as you see the seed breaking the surface. Also, you can water with the shade cloth in place as the water will go through the holes in the shade cloth obviously, but it also protects the seed a bit from having the substrate wash away if watering too heavily by mistake. Now that you have posted this question, Murphys' Law would dictate that your seed will hatch by tomorrow morning! Hope this helps,... Organoman.