little flat bug

Question
i thought one of my fish had white spot on it tail, but i found a little flat white/clear & black spotted bug swimming around the tank and the fish now clean, is this something to worry about!  

Answer
Dear Lee,
Due to some bacterial infection, you have noticed the symptom of white spot on the fishes. Remove the bug from your tank as early as possible. Change some 15-20% of water of your tank regularly within two weeks minimum period gap. Thanks. Good Luck.

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