Skimmer acting weird

[Daddi0]

My skimmer has chugged along for about 2 years producing nice skimmate. The reservoir has liquid and minimal bubbles breaking quickly into liquid. Today is weird, foam everywhere. I dont normally screw the top on. No need to. Today the lid was blown off by the foam and there were bubbles/foam everywhere. I havent changed anything except adding one saucer sized rock to my reef. Perhaps this is normal? I have added rocks in the past with no noticeable change.
Cheers! Mark

 

[mcgyvr]

Sometimes that happens.. Additions can cause changes in the water which can cause a skimmer to go crazy..

Sometimes they just need to be pulled out and given a good cleaning.

These are always temporary things and it will go back to normal either after the cleaning or after whatever is in the water is skimmed out or diluted more..