Coraline Algae on Glass

[stimpy4242]

Just curious, I have now had an established tank for nearly 4 years and while coraline algae growth is noticeable on most LR there is NONE, ok maybe 3 quarter size patches on the back wall of a 125 gallon tank. Why?

 

[btwk12]

what are your parameters? how often do you do water change? and what lighting? my coraline took off when i got my new lights. but im pretty sure you have to have good calcium levels and clean water to get coraline