No charms
No potions
Recommended: Rainbow bubbles
Begin to tackle the infection on the right. I found it was easier for me to take down the left side by bouncing the balls off the wall giving me more effective drops meaning more points. This also stopped the infection, which is at the top on the left, from coming down any lower.
Once the infection is down on the right, the ceiling will be visible. Play your bubbles to drop the ceiling.