Some people swear by them and other's know they're a waste of money.

Interesting sentence that. The Others? Would that be the bad people from
Lost? Don't think they keep koi. But then, Solo & I are idiots and OUR
experience would never be as sage as yours.

User of Sho Koi, Manda Fu, & Hy Fang (spell may not be correct).
$68/year total, feeding 7 large adults and over a dozen fast growing
youngun's. Experience, seen fatty tumors (internal & external) on koi &
goldfish fed cat/troutfish food, and other pet foods. ~ jan

See my ponds thru the seasons and/or my filter design:
http://users.owt.com/jjspond/

~Keep 'em Defrosted~
Tri-Cities, WA Zone 7a
To e-mail see website