You don't want to increase the amount of water as much as you want to decrease water loss. As the soil dries, the roots grow faster, reaching out to find water. Keeping the humidity up somewhat is a good idea, at least until the single-bladed leaves start growing out. We plant germinated seeds in plastic cups about 2/3 full of damp seed starter soil, with plastic wrap over the top. A hole is punched in each side of the wrap, against the edge of the cup.