Hello, I am very much struggling with the guppies I brought on Friday, I had one die on Sunday and another today. The lead up to dying they spend large amount of time at the top of the water, not really loving around much. For the first one they had an orange tail and that went black and then started to rip apart. And kept getting stuck in the filter and not being to control their movement. Then died. the second one which is already has a black fin, presented in the same way of staying at the top, part of their tail went a green colour but with the melafix changed back to normal. He still wasn't swimming around properly but was able to spend some time with the other two guppies (all males). Then today it started to rip, I continued to use the treatment. Then when I get home from being out for the day to find it died being stuck to the filter. It looks as though every time it got stuck to the filter it's tail got worse. Now one of my other gupies has got some cloudiness around the outside of their tail. I'm concerned they will die to, I did a water change yesterday of around 40%. Currently showing 0 for ammonia, 25 NO3, 0 for NO2, 16.d for GH, 6.D of KH, 7.2 Ph, CI2. Could really do with some advice as I am a new tank owner and concerned about where I am going wrong with taking care of these fish.