I bought a secondhand Jewel Rio 180 litre fish tank. The previous owner kept pharanna's in it. I then kept 8 fancy goldfish and 16 danios in it. First the tiny goldfish died (I had just bought her from the petshp but she had a white lump on her back), then a tiny black moor, then a calico, then another calico, then my 2" black moor, then a common goldfish, then another and now the last one being a white oranda (which I have had for 18 months and she is beautiful) is on her way out.
I have treated the tank with esha 300 which cures (supposed to) many things but none of them has been saved. Now, I have taken out the oranda and have her in a smaller tank by herself as she is at the bottom struggling to breathe. She is normally pearly bright white but from the mouth to the back of her gills she has a pink tinge under her gills. I know she has obviously got some bacterial bug or something that is affecting her breathing. That's how they all have gone. I took advice from the pet shop but to no avail each time they have gone down with it. I do 20% water changes every week with treated water, do everything I should with the filter media. Vacuum the gravel and have cared for my fish the best I can.
I am wondering if there is something wrong with the tank. Doe anyone think that it is because I used a tank which previously held pharanna's in? If they had a bug, do you thinkg that it has inpregnated the tank? Why, after all the good care I have taken and tried treatment etc, they have still died? By the way, they have died over the period of around 6 months or so. So I have lost one at a time every other month or so. I also only have 8 danios left.
Please help. My oranda is on her last legs, is there anything I can do. She was the best one I owned and a wonderful specimen. email@example.com