I am considering installing a small pond in my garden next spring (probably 40x70 and 50cm deep). I don’t think I want to have a pump but I do plan on having some oxygenating plants and a dwarf lily. From what I have read in books and online, this is a terrible idea and I should have a much bigger pond with a pump/filter. Can anyone advise on their experiences with a small pond? Did it lead to any issues? Do you get a smell from the stagnant water?