In my last post I had said my Fire eel was not eating but was still as active as normal, well today he was in his cave upside down but moved when I tried to touch him, He did show a little interest when I put in some Mosquito lava but has now just lay under a rock. I redone my water tests and all came back normal apart from my Ph was 6, I did a 25% water change and added alittle Ph up and will do the same again in the morning. I have had a DIY CO2 system running but have taken it out thinking the co2 drove the ph down. Any ideas as this is only the second Fire Eel I have kept and my last one died after having it only a month. I normaly do 2 x 25% water changes a week and every third week I will do a 50%. He is in 400L tank with a few Danios, Minnows, Barbs and SAEs so he is not being bullied as he is by far the biggest in the tank. I would hate to kill another Fie eel as they are very cool fish.