Ok i used to have some gourami's in a 20gal. And after a couple weeks their eye's started turning red. Some days it was worse some less. Besides that htey were completely healthy and happy. I've recently sold them to someone else. I put in some mbuna for a while who weren't happy there so I moved in some guppies instead. I'm just wondering what caused the red eye and if it'll harm my cichlids or guppies. Thanks.