Adding CYA

Donldson

TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
3,970
NW Ohio
The skimmer method works but has some drawbacks: it can clog pipes, it can get washed out of the filter if you don't get it long enough, and you can't tell for certain when it is all dissolved.

The sock method avoids these problems.