Betta with bulging - red eye.

Question
We have a beta that we have had for almost a year now (just a couple weeks shy).  I change his water once a week (on wednesdays)  Today I went to change his water, and saw that he is floating on his side, and that one of his eyes is bulged and red.  The side with the bulged eye is the one floating up.  He hasn't been eating very well for the last couple of days.  He is an only fish.  His water temp is 77F right now, and usually ranges from there to about 79F.  He lives in a small tank, it was a "beta kit" at the pet store.  I'm not sure of the size.  Do you have any idea what could cause his eye to do that?  Or what I can do to help him?

Thanks so much!

Answer
Hi Nikki,

Your fish sounds like he has popeye, a bacterial infection brought on by bad water quality. Since you change the water weekly, maybe the tank is too small and ammonia (toxic waste) is building up too quickly. I reccommend at least a 4 litre (1 US gallon) tank for a betta.

As for treating the current problem, get a good broad-spectrum fish medication. I recommend Wardley's Promethyasul but any good quality brand may help.

Try adding some AQUARIUM salt to his water - not table salt, it can kill! There are many good brands, most of which will be available at your local fish store. Keep his water clean, change it twice weekly now. Keep him warm - 24-27 degrees celcius (78-82 fahrenheit).

I hope your boy recovers!

Prue