Correct about timeline. Around 7 years for that build up. At first I loved it because my bare rocks were getting covered by a FEW of them without my intervention. They placed themselves where they wanted. Even on the back glass. Slowly until the last year or so then the explosion happened. I have to remove some weekly or even daily when they float around and get stuck on my wavemakers and overflow!! It's a shame I have to flush them though!