I bought a complete fish tank ensemble 3 weeks ago, treated the water as instructed by the pet shop and left for a week before introducing fish. I bought 5 neon tetras and was planning to buy more 2 weeks later. Today i found 3 fish trapped around the bottom of the filter and another missing- nowhere to be seen. I now have only 1 left and i am worried he won't survive as he is looking stressed. Any idea why the fish would have got sucked towards the filter? I feel very sad!