It isnt crazy. If you put joghurt in the water it doesnt mix with the water. Best is you put it on a stone.
An extract from the "Amazonas Nr.10 March/April 2007 (translated of course)
No, no, not what you think... . This isnt a new crazy joghurt creation. I want to present you new food for fish, especially catfish.
Everybody knows this situation: Youve bought a new fish and after the euphory, to have a new rarity, comes the bad part. The cats, especially from the family
Loricariinae, for exampel
Lamonichthys-, Pterosturisoma-and some
Sturisoma are like in your worst dreams.
Sympthomes are hollowed bellys, apathy and bad looking. Those things happen because of the catching with the net and using antibiotika after catching. The fishermen give them to much medicament, so the bacterias of the gut die. Hunger and stress damage them too.
You have to use bio-joghurt. The idea using joghurt for fish isnt new. 1980 joghurt was used first time. After buying a fish you couldt give them a half tea spoon every 2 days. When you give the joghurt in the water, you should put it on a place, where the fish could eat it. Look, how much they eat and how much you have to give them. If there is still a rest of joghurt after one day it shouldt be put away.
You could feed it every week in your tanks. Especially after giving medicaments its good for rehabilitation. cichlids, tetras and livebearers like joghurt very much. Just test it yourselve!!!