Sorry if I (we) have thrown too much at you at once ... just trying to be helpful, but maybe to a fault.
Not to sound like a jerk or anything, but since you are new, I want to be absolutely sure ...
You said you run the pump 6 hours and the SWG for 4 hours .... these are at the same time right? Because the water needs to be moving through the SWG for it to function.
The fact you said different times raised a flag and another possible reason for 0 FC. Most basic systems are slaved together on 1 switch/timer so the pump and SWG are always on at the same time and the chlorine output amount is adjusted by a dial as a % output while it is on.
But, based on the fact you have ONLY added salt (which is kind of good as you have not messed anything up with metals, etc and not spent a lot of money of products that you do not need) we can be sure your CYA is 0.
Next play is exactly what the expert Jason said ... get some CYA in the water and your FC level will rise from the SWG (although you probably should add some bleach to help get the FC level up before everything turns green). I believe I have read that many Walmarts will have the stabilizer/conditioner/CYA.
Depending if you find the liquid or powder CYA, there are different methods of adding it to the pool. According to the
http://www.poolcalculator.com (check this out if you have not). For 5000 gallons, you need 47 oz (3 lbs) powder OR 121 oz of the liquid to get up to 70 ppm assuming a current level of 0.
Post back with what you are able to find and someone will certainly help you out.
Once you get things started and stable and continue to learn by reading Pool School ... it will become easier. And then you can lounge by your sparkling pool.