Pumps Clogged

Both my mag drive and koralia keep getting clogged. And by clogged I mean the impellor stops spining. I took both out and soaked them in vinegar and they are fine now. But I just did this once to my Mag last weekend. Is there something in my water causing it to get blocked up like this?

 

It could be calcuim carbonate. I am toping off with kalk. There was crusty stuff on the magnets on the impellers it was green though.

 

No Its been very clear. Its weird though because I knew it was happening with the koralia because when I unplugged it to feed my coral and plugged it back in I had to tap the impellor to get it to start. But I came home today and both the mag and the korallia were dead. I had just cleaned the mag the last weekend.