i have heard from different people, saw videos and read articles on internet that Epsom salt is necessary for cichlids. so i went to market to find Epsom salt and i only found it in a laboratory shop with a name MgSO4. 7H2O (Epsom salt) in a bottle which was a white fine crystal powder. when i was going to buy it i suddenly saw one more thing written on the bottle top * POISON * . i am now really confused that weather to buy it or not . if its good for fish why its written poison on it. plz help and suggest.