Dealing with slug like objects. Been installing ponds for some time, but homeowner's always wanted to do their own maintenance. I am maintaining this pond (newly installed fall 2015) and have never come across this before. I picked some up and it is not slugs. One koi and some goldfish. No issues on fish (monitoring one fish). My first thought is dying algae since algaecide was installed middle of March. Any thoughts helpful.

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