The switching of light itself isn't going to do it...but you have to keep in mind the wattage difference between those 2 lights. If you had enough plants going/big enough area to warrant a 1kW light, then the switch to the 175W lamp would have been only a fraction of the light needed for said area/plant number.
If you only have enough plants/area to "need" 175W MH, then that 1kW HPS is a bit of overkill...though if you can control the heat then it shouldn't /hurt/ anything.
The two different lights are really for covering different spectrums that are beneficial during different periods of growth. Most folks like HPS for flower, but MH for veg. However you'll usually see people using lights a bit closer in power than 1k vs 175. Others like to use both during flowering just for extra energy and the theories that the blue light helps a bit with potency in the end.
You're not going to have shock or issues from just switching spectrums. Switching to a light that is way too little power, or way too much power might have in impact though.
