PLEASE HELP ! I have 2 goldfish with a golden dojo loach in a 20 gallon tank. I've had them for about a year now and everything seemed fine untold a few months ago. I accidentally dropped their food container in the tank one day and ever since then one of my goldfish has been unable to open its mouth :( I've treated him for internal & external parasites but nothing has changed. He is now close to death because he can barely open his mouth to eat. One if his gills also barely opens. I don't know what to do so please leave any suggestions asap ! Thanks :)

Well, wow. There could be a lot going on here. I have no idea why dropping a container of food in the tank would make it hard for a fish to open his mouth. But I do know that a whole lot of food in a tank can cause havoc with your water chemistry, which can result in all sorts of health problems with fish. What did you do when the food fell in?

Ideally, you removed all the food particles with a net and then did several partial water changes to remove the rest of it. And then you monitored your pH and ammonia levels every day for 7-10 days, to make sure you were not having an ammonia spike.

While we are on the subject of water quality, what type and size filter do you have on this tank? And you should know that a 20 gallon tank is too small for 2 goldfish, unless you have a top-of-the-line filter on there, AND are doing weekly water changes of AT LEAST 50% or more... even then it's pretty small.

At first the water vacuum and partial water changes were not enough to get all the food out so I did a full water change. & the guy at the pet store told me that a 20 gallon should be eno0ugh for 2 goldfish ! I didn't know :s I do about 70% water changed weekly & I'm not sure about my filter size but it looks pretty big? Someone else has suggested that it might have something stuck in its mouth or that it has streched its over extended its cartilage and is permanently locked :(

Sorry it took me so long to get back to you... computer issues. I think a photograph would be immensly helpful here. If you were to post 2-3 clear pics to this thread. ** edited**

I am there all the time, and will keep an eye out for your pics if you come back here and tell me that you have posted some. Once we know specifically what the problem is, you will get the help you need. Otherwise, it is all guess work.

Regarding the size of the tank... fish store employees mostly mean well, but have shockingly little knowledge. There are, of course, some who really know their stuff... but the vast majority are very limited in what they know, or THINK that they know. I could tell you stories... Also, keep in mind that they are in business to SELL you stuff, not TELL you stuff. If they think you want a 20 gallon tank and 2 goldfish, they will OF COURSE tell you that a 20 gallon is OK for 2 goldfish. They won't tell you that it is BARELY big enough for 2 small fancy goldfish (not comets)IF you have a VERY good filter, and keep up on your water changes, AND don't expect the fish to live long enough to get any bigger...

I am sorry, 20 gallon tank ? I am sorry that seems very large for two small little fish.

A 20 gallon is not a bad size for a small group of community tropical fish, but it is too small for two goldfish for anything more than short term. Goldfish (if they survive) grow fast, and have the added problem of a high rate of waste production. In other words, they don't use their food as well as many other fish, and more poop is produced. Some people call goldfish "dirty" for this reason, but I do not like that word... it implies something negative. It is just a biological fact...

I love goldfish. Other than a brief experimentation with some tropicals way back in the 1980s, I have only had fancy goldfish. About 10 years ago, I branched out a little and started two ponds in my yard which now house comets... the more basic form of goldfish.

A very general guideline that many seem to agree with is 20 gallons for the first goldfish, and 10 gallons more for each additional goldfish. And go for the best filter you can fit on the tank!

I think the water tank water is main cause of any such type of issues. Because it may be possible that mix of any unwanted material particles like as you described dropped their food container in the tank due to that ammonia spike may be mixed with water. So make sure that water is pure all the time. Even regarding your problem you may contact with fish specialist parasites.