Hi there, new to the site! In real need of some help asap! My ember tetras were acting a bit lethargic this afternoon, my temps been 21c since I got the tank, though I only just got a thermometer and had wrongly assumed that it would actually keep the tank at 25c as advertised. I did a bit of research and saw that it could be due to low temps so I went and bought a new 50w heater. I put this in with the old one to get the temp up to about 24c. It's now the night here and 1 of my embers is clinging on for life, and another 2 are floating around out of control. One has gone missing and the rest are at the bottom being very still This is my first tank (in a while) set up about a month ago, which is a Biube 9.1g (no hate please). I cycled with Tetra Safestart and added 4 ember tetras from the advice of my local fish shop. Everything went very well for the first few weeks. I took some water to be tested after about 2 and a half weeks and the shop said not to add anything else yet. I waited another week and went back and they advised adding another 3 ember tetras which I did. They seemed to acclimatise well and were swimming and schooling up beautifully.That was on monday morning and it's now Wednesday night. I don't have any test kits and it's the middle of the night here so I can't get one any time soon. One of the ones at the bottom seems to have a twisted back, though I'm not sure if I've only just noticed that. Could this be a mini cycle? The shop didn't tell me my exact water readings though he said my Nitrates were still fairly low but so was everything else. I've not been feeding much to keep Ammonia down and up until today everything has been going great. The only other possibility I can think of is Neon Tetra disease, I must admit I didn't quarantine so is there a chance of a disease? Any help would be appreciated as I have no clue what to do Cheers!