I went to the official Prodibio website, but the details are minimal. It could be lost in translation since the company site is French, but essentially it's microfood. http://www.prodibio.com/growth-development-corals-aquarium-saltwater-reef-booster
It took my skimmer about an hour to get back to normal, and a full gallon was exported. I readjusted it to lower the water level in the skimmer's body overnight.
I've always been leery about this one, but the company's owner has told me every year to use it without fear. A pro vial is rated for 250g, so I've used one vial every 15 days for the past month. I didn't see any downside like algae or cyano, which would be the primary concern not to use it in my tank. I'll keep watching and seeing how it works out.