Rare time for me to have 5 minutes at the PC.
K1 shedding it's bacteria has been a problem for many in the UK.
I've been running the media for 2 years June just gone. In that time I have only suffered the problem once and I was the cause I am sure. I was off to Japan for a trip so to help my good wife Lynn; I cut feed levels prior to going so as to make filter maintenance easier. Within two days the water was cloudy and the media stripped back to white.
I think the reason I have only suffered this 'shedding' once is because I run far less air than many. If the air delivery system is well designed, the media can be made to churn with very little air. I have 350ltr of Kaldnes in a 40" vortex and the whole lot rolls along like 'poetry in motion' on 30ltr of air.

Here is an MPEG clip of this system. On my media player it runs a little fast for true life speed, but you can see the water is not boiling, just rolloing.
http://www.koi-uk.co.uk/filter_systems/k1movie1.mpg
Maurice.