replace light bulb induces cynobaterica??

[mandarin man]

Beside doing water change and clean up the cyno, I guess I just let the system balance out again.

My first impression was the since the ceramic biological filter created nitrate, I wanted to replace it with live rocks. And I always thought that my tank is now 5 months old, it should have enough "good" bacteria not to throw anything off balance even introducing new rocks. I was wrong.

I have another question. I placed rubbles at the back of the Red Sea Max where the RSM skimmer used to be; however, there is not much water flow there (very little water flow), this is because I took out the orginal RSM skimmer replaced it with the Tunze. Lived rock but minimum water flow. Do you see anything problem with it? Nitrate issues (dead spot)?