Black Moor seems ill

Question
29 gall. tank
4 goldfish only and 4 algae eaters
Change water probably every month and a half
replaced probably like 3/4
 My daughter noticed the Black Moor has a different color (not as black as it used to be) and his eyes seem to have like a blow up film over the norm.  As it is the Black Moors have their eyes popped out but they notice him having like a bubble over it.  What can I do to help my black moor?

Answer
Hi Eva;

If his eyes have a whitish coating over them I would suspect irritation, injury or infection. He may be getting bullied by the other goldfish or the algae eaters. Watch your fish for a few minutes from a distance (so they aren't responding to your presence). Let them just act naturally and see if you can catch any of them "misbehaving".

Those symptoms also be from dirty water. Your tank really needs to be cleaned more often to maintain a more consistent water chemistry. Change 25% of the water and vacuum the gravel every week. Goldfish are very messy guys that just need very frequent maintenance. If we wait longer than a week or two the water chemistry degrades too much and too much waste builds up. Even though clean water is good, it's very different from the old water and can shock the fish.

You may notice your moor improving very quickly after a water change. If so, great! If not, he may need more help. Add aquarium salt and a product called "Melafix". They can soothe irritated tissues and aid in healing. Let me know if you notice other symptoms...

At Your Service;
Chris Robbins