Zoa closed at 100 Par??? Light Par was lowered about a week ago?

I got got a frag of zoo with about 10 heads. At first, it was pretty open but I lowered my light power because it was too high when I tested it with a good par meter. After adjusting the light, the par is about 100 at that location. Is it likely closed because it needs more light or something else? The light power was lowered about a week ago.