If you added all at once, then very likely cycle will startover. However, you could either cure the rock in a trash can for a couple weeks first, OR, added new LR in one at a time.
I have a 150 gal tank running a little over a year now It has about 75lbs of life rock and about 100 lbs of life sand . I would like to add more life rock . Will this cause the tank to go thru the cycle phase again ?
I now have a Yellow Tang and a Percula Clown in there . Also assorted crabs and snails .
The third option is to add cured LR to the tank. Keep the LR covered in wet newspaper on the way home from the LFS or wherever you bought the rock. There will probably be a slight die off, but nothing serious.