Sulfadimidine, which is also known as sulfamethazine, is widely     used in veterinary medicine in combination with chlortetracycline and     penicillin  

Maracyn Plus safe for display? Ahhh...no. 9/1/04 The guy at my LFS insists that Maracyn Plus (encapsulated Sulfadimidine + Trimethoprim) is safe for display tanks with live rock and inverts. <hehhehehehhehhe...hahhahahhahhah... wooooooo hoo! Ahhh... no.> I am not convinced. <healthy and accurate skepticism> What do you think? <unquestionably not safe to many desirable life forms. You do know/recall the root/def of the word anti-biotics? "against-life". This medicine WILL harm and  kill desirable and undesirable microscopic organisms and facultiers (like your living filter/live rock)> I've got a Sailfin with a cloudy white area on caudal fin that may be a fungus infection. Symptoms so far do not shout ich or velvet. Thanks, George. <most all sick livestock are best removed to a proper QT tank for these and other reasons. Anthony>