Hi. Just wanting some advice, I currently have 4 guppies 2 endlers and 1 rosy tetra. I did buy two rosy tetras and the 2 endlers together and added them to the guppies. I always noticed that one of the tetras was reserved and stayed at the bottom a lot although still fed and swam every now and then. I found it dead today, so I now have 1 tertra left but they have never swam nor I don't think they would normally swim with guppies and I'm worried about it being alone. I questioned the guy at the shop if 2 would be okay with other guppies as I know they like to school with the same species but he said they would be fine in a pair. The more I read the more that sounds wrong. The poor tetra that's left is now just sat at the bottom when it would normally be the lively one of the two. I would just go out and buy more rosy tetra to give it a schooling group however my capacity it pretty much full for my 25L don't want to be adding that many fish. Also to add... my filter failed on me the other day, whereby they went about an hour without filtration till I bought a new one. My other fish are fine but that one is now dead and I'm not sure if it's that that caused it? Not sure what to do next for my Lonely tetra and I do regular water quality checks and they are reading fine