Possible Disease Outbreak!

[itsgoodsince1889]

 Okay, It all started when 1 of my 5 guppies developed this mysterious disease, and not long after he started showing symptoms for it, died. Now, one of my other guppies is starting to show the beginning symptoms: white stringy poo, swimming tilted upwards at surface, in back corner of tank... I'm afraid that if i don't treat the tank soon, all my fish will become infected. The guppies are in a 20 gallon tank with 3 Tetras and 2 peppered Cory Catfish. I tested the water and it is fine.
Thanks in advance to anyone who has any suggestions

 

[mark4785]

White stringy poo is a typical symptom of a bacterial infection caused by internal problems of which are usually parasite-related.
 
I'd advice that you treat the tank with an anti-bacterial named WaterLife Myaxin and begin to feed all of your fish peas that have been cooked but which have cooled and are mushy (remove the outer-skin). This source of fibre from the pea will speed up the fishes digestion and therefore help it to expel the internal problem.
 
Hope this helps.