You used 5* the recommend rate?
5.2 is a blend of sodium salts of phosphate, so you added a lot of sodium. IIRC Kaiser added 5.2 to some water and got in analyzed and at the recommended rate it added about 100 ppm sodium so you added 500 ppm sodium. I doubt that is going to negatively affect fermentation, the beer may or may not taste a bit salty. You'll have to wait and see.