Notice a green algae forming on my rocks after putting on new pc light fixture on my 30 gallon tank. Could it be from the light being to powerful? It is a 2x 95w. Tank is about 1 year old. Everything tested normal. Here are some pics.
Your lights aren't too powerful. You're going to see changes like that every time you upgrade lights. Do more frequent water changes in the meantime, and make sure you have a good cleaner crew. Running a phosphate removal media will help also. It will go away in time.