About a day ago the bulbs had been switched from the MH bulb to the HPS and seems as though the plant is now droopy. -The soil is still moist(Watered a day before the switch) Can this be from the change of light that the plant needs to get used to?
Its the lack of blue in the HPS light spectrum. When a plant loses out on the blue it starts to stretch and becomes droopy. Most people use HM specifically for the blue. The HPS light have the "mid-day" light spectrum with orange and yellow. If I were you id go with the "enhanced performance HPS" which has a wider spectrum of blue light as well as the orange and yellow flowering colors. Or maybe you could just put one HM per 2 HPS. Hope I helped
The HPS bulb/Ballast is supposed to "Creates a more correct balance of red and blue/violet energy for increase photosynthesis"
http://upload.wikimedia.org/wikipedia/en/c/cb/High_Pressure_Sodium_Lamp_Spectrum.jpg http://upload.wikimedia.org/wikipedia/en/9/93/Metal_Halide_Lamp_Spectrum.jpg The first pic is HPS light spectrum and the second is HM. Notice the difference in blue and violet from both lights? Your plants definitely do and react to the change.
I totally doubt it, it could be alot of things. You said you watered it 2 days ago and the top of the soil is still wet then theyre probably a little overwatered and pissed.
Yeah it should, Ive seen this happen before. I dont see why it wouldnt recover unless there are other problems.