Some questions about a Mississippi Map tank setup

[flyingpenguin28]

I am buying a map turtle hatchling. So far I have bought
-40 gallon tank
-Marineland Bio-Wheel Penguin Aquarium Power Filter
-Eheim Jager 125w heater
-Zoo Med Aquatic Turtle UVB & Heat Lighting Kit
-Zoo Med Turtle Dock
-20 pounds of 1/2" smooth rocks
-API Turtle water conditioner

My questions...
What should the water temperature be versus the temperature of his basking spot?
What should the ph level, ammonia, and nitrate/nitrite of the water be?
Should API Turtle Sludge Destroyer be used during initial setup or just when it gets scummy?
And I keep seeing different answers online, so how deep should the water be in the tank?

Thank you!