Hi, this is my first post but was hoping someone could help me with what I should do. I have never had a fish tank before and up until the part week or so haven't actually liked fish that much (got a tank for my 5yo who loves them). Anyway, I have recently started the tank, cycled the tank for approx 2 weeks and went to get water tested at the aquarium and all was ok so bought 2 male guppies. One died of a bacterial infection 6 days later and the other survived. We have since battled with ammonia levels and I have been doing 60%+ changes twice weekly and adding all of the stuff I was told to add. I have fine to the aquarium twice a week every week and each time the ammonia was getting lower but still there. The surviving fish was very quiet and inactive for the first couple of weeks and then as the ammonia started to drop to lower levels became quite active and is a very friendly fish. He started following me around the tank as I cleaned it, and every time I would just go and look at the tank he would come to the front and hang around looking. He also would nibble my finger every time I put it in. He is this beautiful silver and yellow guppy with black spots on his tail fin that remind me of a leopard (his name is Leo). So he seemed very happy in his little environment and he made me actually enjoy having a fish, and yes I sound weird growing fond of a fish I know. I really like this fish! But anyway, today, approx 5 weeks after we started cycling the tank and only having Leo we got the water tested again today and finally the ammonia was gone and the water hardness was up and they said we can finally get more fish. So we chose a pretty swordtail and 2 more male guppies. Took them home and introduced them to the tank and later in the night I noticed that Leo's tail fin was looking a bit worse for wear. I watched for a little while and the two new guppies were hanging around the heater and he was just sitting at the bottom of the tank the whole time. When he would dare move, one in particular would constantly chase after him and nip his tail. He has had chunks bitten off by the look of it. So I got a container and separated him, but then went back later and he must have jumped out of the container into the tank and I'm guessing had another go at Leo as his tail looks even more sad. So I segregated him again and put glad wrap on the container with plenty of holes but at least he couldn't jump out. I have no idea if this will allow him enough oxygen but I can't leave him in the tank eating my favourite fish! Leo seemed to start swimming around like normal again and then I noticed the other guppy, who seemed to be placid earlier, also having goes and biting his tail and then he started sitting on the bottom again looking all sad and miserable and I felt bad for him (two guesses as to my gender lol) so I also put that guppy in the time out container. The swordtail seems to do his own thing and doesn't bother anyone and he is the biggest fish of all. The aquarium told me that usually the fish that are already there would be the dominant ones but he is just running scared and not fighting back at all. I'm so worried he will die, and also really mad at the guppies eating his tail because he was so beautiful and now he looks all injured and miserable. The aquarium told me when I bought them that if the swordtail was aggressive (as is the higher fish) to bring it back, so I will take the two guppies back but can't do so for another 2 days due to working the hours the shop is open. Will taking the fish back solve my problem at all or will this happen with any fish I get? Would it have helped if I had just brought home one fish at a time? Should I stick with only Leo (if he doesn't die) in terms of guppies and add swordtails or something else instead? Sorry I know this is really long, well done if you got this far, any advice is much appreciated. I can't call the shop as it is almost 3am.
TIA
TIA
