So I recently inherited a koi pond with the house I bought. Not knowing what I was doing I put too much of a cleansing chemical and killed two out of the six fish I had. I have changed the water several times and the four remaining fish seem healthy except for the fact that they constantly hide. They used to come out only when I fed them but it seems like they are barely even doing that anymore. Where they are hiding is behind a flap of the liner which seems redundant, should I cut the flap so they can't hide there anymore? I don't really want to do that but my wife really used to like watching the fish swim around and thinks I should cut it. Is there anything else I can do that would make them happier and more playful like they used to be without taking away their hiding place? Any advice on this or any tips in general would be great. Thank you so much for any help.