Fish has spots and fins deteriorating.

Question
Chris - see below for answers... thanks!!

Hi Kal;

Make a 25% water change today and another tomorrow. This should help them feel better until we can find out what's going on.

Do the spots look like patches or more like salt specks?

> Hard to tell, they are not as small as salt grains, but are shaped as such.  They are maybe a milimeter or two across.  They are definitely not large patches of white.

How big is the tank?

> 20 Gallons

How big are the fish?
> About 2 inches each.

How often do you make water changes?

>50% change every 3 - 4 weeks.

How long has the tank been set up?

> Six Months

How long have you had fish in it?

>Six Months

What kind of filter?

>Biological

How often is the filter cleaned/changed?

>At water change, every three to four weeks.

Let me know as soon as you can.....

Chris Robbins


Answer
Hi Kal;

It could be a parasite. Parasites are best treated with salt. Here is a site with a formula for using it;

http://www.goldfishinfo.com/salt.htm

Here is more about spots;
http://tinyurl.com/9zrbd

Here is info on ich, the most common cause of spots;
http://www.netpets.com/fish/healthspa/ich.html

For maintenance in goldfish, 25% of their water must be changed every week. Waiting 3 or 4 weeks and doing 50% is really hard on them. They are very messy fellas so they need more frequent smaller changes to stay strong. Try to avoid fully cleaning the filter at the same time as a water change. Clean only part of it so the system isn't stressed. Beneficial bacteria lives in the filter as well as in the gravel and on decorations. If it is disturbed too much it will not be able to filter dissolved invisible wastes effectively. This makes the fish much more prone to disease.

Let me know if you don't think we're on the right track. Hopefully your fish will be feeling better very soon.

At Your Service;
Chris Robbins