Question about seedling light heights

Currently starting a batch of seeds. Only grown clones until now. How high should my 2ft t5 lights be away from my seedlings? They're about 3 days old. Right now the lights are about 4" above them.

Here is a pic as of now

Keep the light as close as possible their whole life. You can easily judge this distance by placing your hand at the very top of the plant. If it's to hot for your hand, its to hot for your plants.
Keep them at a distance where they can feel a very small amount of heat.

Awesome thank you. By whole life you mean from seedling to flower?