Hi everyone I am new to this tank business. I started with 10 ember tetras' 3 guppys and 2 male pearl gouramis . One of the gourami became aggressive to the other so luckily the pet shop took it back. Everything has been fine for about 4 weeks then all a sudden the remaining gourami killed one of the guppys . Then one of the remaining guppys killed the other guppy . Sorry I hope your keeping up. Again things were fine for a few weeks. Then a couple of days ago the gourami shredded the last guppys tail to bits. I removed the guppy out the tank. That left the embers which this morning were no where to be seen. One appeared and the gourami went mental trying to catch it. The gourami is now in a tank on its own. slowly all tetras appeared from where they were hiding poor things were terrified. Any ideas anyone?? By the way all the fish I brought were all on the advise by the pet shop they were ok together mmmm .