It might be as simple as transplant shock, but...

If noticibly worse every day, do the flush. But once you start doing things back-to-back-to-back...stress will set-in and a diagnosis get's that much tougher. (overfertilizing, transplanting, changing the ambient enviornment, overwatering...) You'll want to avoid keeping the roots saturated, so if you can, hold off till the soil is ready for more moisture.

Mind me asking who it was that told you to add regular doses of 10 drops of Superthrive in addition to your pre-ferted soil? And this was every 3 days...?

You do realize that every time you water, nutrients are being released, right...?