It could be leaking from the hoses, water pump, head gasket, a number if places.
If you clutch fan is working EFans won't fix anything, you have another issue.
Pull a plug to see if it's really clean looking. If so chances are you have head gasket issues. When water leaks into the combustion chamber it's steam cleans the plugs. Also check your oil to see if any water is in it.
Oh and FYI, you DONT need coolant. Straight water cools better than coolant actually! Coolant is used only to lubricate the system and prevent from freezing in winter months. So with that being said if you are loosing coolant just keep replacing it with destilled water until you find the leak.
I would start by getting under the truck and looking for leaks, checking oil for water, and replace radiator cap.
Silver 2013 F-150 5.0L FX2 - Leveled/Lifted-275/60R20 Nitto Terra Grapplers-Airaid Jr Intake-Resonator Delete-SCT Tuned By MPT
Built On 11-15-2012