is sad. And I must preface this with this note: I do not know the maker of the specific island product I speak of. I am not being malicious, but sharing some information for all newbies who may be thinking seriously about what is best for their koi. Just trying to point out truths so others can see why we speak so vehemently on 'no structure in a true koi pond'.
This hobbyist has a well built, 6' deep pond with approx. 12000 gals volume, Nexus filters, etc. Thought he would try a 'floating island'. Put in last summer - 06. Well, late summer, 2007 he was checking the fish one day and noticed a rather red line across the shoulder area of one of his largest koi (20+ in.) A closer look revealed the existence of a piece of heavy 'fishing line' cutting into the fish. It was the circle of fishing line that had been installed from the floating island in the center of his pond to the shore to anchor it. It came loose from shore, floating in his pond, and his koi swam right thru the center of that circle of line. AND, she had been swimming around pulling said floating island (very large one I might add) for quite some time, creating a rather deep laceration across her mid section.
Long story short, made a true believer of him! Called to ask for help and to say "Now I know why you guys said you didn't like these things".
We all must sometimes 'learn it the hard way'! (the koi is OK, now indoors recuperating in Q tank for the winter, but will probably have a perm. scar)