Hi all, new to pond life and i need help please. I live in UK. I have posted a video showing my pond. It's a new pond build and was crystal clear, I've added some plants and the whole pond has gone a green merky colour and a slimy substance is clinging to everything. I've treated it with an anti Algea chemical but 3 days later no improvement. Please take a look at my video (link) and any advice or thoughts would be appreciated.