hi im dawn and have had a pond for about 10 years. it was really nice with a waterfall and a nice amount of fish. i went away for a weekend and when i got back found a large dead fox in the pond it had obviously died over the weekend! it had polluted the water and my fish all died.its been neglected ever since and is still full of water leaves and sludge,the pump doesnt work anymore so please id love some advice on how i can get it back to how it was before and where do i start?