Installing Radiant in my garage, I have a bunch of ? head is spinning

[JOE G]

I have it installed now, Going to be pouring today, 4 Runs about 200 Ft each about 8 Inch between runs, I hope it does well. My slab is about 5 Feet underground in the rear, And 3 foot under ground on the two sides,m the only part that isn't under ground is in the front.