floating basket

I purchased this floating basket at the end of last year and used it all winter long (with a round fiber placemat inside) as a sort of cover for the fish to hide under.  The original purpose of the basket is to be used as seen here:  it is a place for floating plants that will protect their roots from hungry fish.  I put one water hyacinth, one water lettuce and a small piece of some other floater in the basket.  As I thought might happen, the basket area filled up with what looked like mosquito larvae because the fish couldn't get to them to eat them. I also saw very, very tiny fish fry (which have now disappeared).  I tipped one side of the basket into the water to try to circulate the water better, which sort of worked.  The occasional fish makes their way into the basket area, hopefully eating any mosquito larvae they find.  However, I noticed the large spotted koi actually IN the basket the other day!  Hopefully that won't happen too often and these floating plants will be allowed to flourish this summer.