Nasty stagnant pond
My tiny garden pond has a butyl liner and was doing fine until I was unable to garden in the autumn and all the apples from my fruit trees came down, many of them into the pond. Result - disgusting, stinking black water with what looked like an oil slick on it. Now emptied out although all plants but one died. There seems to be a slimy slick on the liner. Can anyone tell me how to clean it before I refill it? Just ordinary disinfectant or something more wildlife friendly? I want frogs to take up residence but shan't have fish.