Yes most definatly on the skimmer. Most additives will throw your skimming out of whack and then produce a TON of tinny air bubbles in your tank. After adding these just leave it off a coule of days. Below is a tech write up on the bak pak series. As far ar the UV it wouldnt hurt.
HTH
The surface tension of the water has been increased by the addition of additives such as medications, stress coats, dechlorinators or conditioners. Use of these products will prolong the problem. If medicating, disable the protein skimmer by submerging the airline into the water (remove muffler first) or shutting off the air valve for 24 hours
