tank is 270l/71g. dont know the parametres. ph is 7. bought a master kit online few days ago that should be here tomorrow so will add the ammonia, nitrate and nitrite levels then. i had my eel, a bala shark, red tailed shark and bristlenose catfish orginally 4 years ago. around 6 months ago the red tailed shark for a reason i couldnt find? two weeks ago i bought 4 african cichlids and an oscar, obviously that pet shop sucks as they said theyd all go good together but had to take oscar back cus it grows huge and nipped my bala sharks fins. ive bought a new high powered internal filter two days ago, new light, new deco. ive really made my tank more homely for all the fish but my eel has chosen to get sick :/. i also noticed theres a lump around its anus..