@Shawcabelguy, when a coral gets stressed and loses its color, (expels it's zooxanthellae) it's cause can be from multiple different things. In your case, I can say that your lack of nutrients (N03 and P04) may have started this. Of course a more mature system most of the time will have those present, along with more beneficial bacteria. Adding some live rock is the best way to jump start your biome, not coraline additives.
I would address the lack of live rock, lower the frag down to the sand bed, preferably in a shaded area or reduce your light intensity and photoperiod. If there is tissue left, though bleached, there is always a chance it can come back.
Aside from a new tank, do you dip your new coral frags in coral dip? If not, do so going forward. In your case I can't rule out a possible coral pest.
To get your nutrients up, if running a skimmer, turn it off for a few days and consider dosing Nitrate and Phosphate to get your numbers up. And get some better test kits such as red sea or salifert.