Poorly Fish : (

Question
Please help. I have recently (2 months ago) changed my two fish over from a fifty litre tank to a 100 litre tank along with introducing two new fish i have had my two biggest goldfish for two years (one black moor and one i won on a fair - standard fantail) The two new lionhead goldfish have been nipping the fins of my older goldfish and now my fantail goldfish has red streaking in his tail fin and it has split slightly also my black moor has what look like crusty eyes! (covered over with something cloudy) Should i remove the new fish to stop it getting worse and what should i do to treat it? Is it the same disease/bacteria that can be treated at the same time? Are they dying? They just mope around i don't think my black moor can see.

I recently did a water test and the pH is 8.5 ammonia 0.1 and nitrite seems to be 0.1 (ish) looking at the colour. We do approximately a 30% water change each week. I don't know what filter i have it is about 25cm high x 8cm wide x 8cm deep and goes in the tank under the water.

I know that is a lot to take in but im really worried about them. Many Thanks

Answer
Hi Lorna;

I would take the new ones back to the fish store. It's just too many fish for that size aquarium and they are going to pick the others to death if you don't anyway. Goldfish are very messy guys that need lots of space. Each one needs 40 liters or more all to itself. Traces of ammonia and nitrite are signs of overcrowding too.

If there is any ammonia or nitrite present in a tank it means something has gone wrong with the biological balance or the system isn't mature enough to handle a full load of fish. It was probably higher a couple of weeks ago and has gone down as the new tank has tried to adjust to the new fish. The Break-In Period can be very hard on fish and takes about 6 weeks. The beneficial bacteria that keeps wastes low hasn't matured enough in a new tank to keep ammonia and nitrite at a safe level for the fish to tolerate. When new fish are added the bacteria has to compensate once again by growing more colonies and that can take a week or two to stabilize again. New tank and more fish was just too much for your system to handle. Here is a link to my page about it that tells you what's been going on in there and how to help your fish cope;

http://www.xanga.com/Expert_Fish_Help

To help the sick ones feel better, make a water change of 25% right away. Do it again tomorrow and also add aquarium salt to the tank. Don't use table salt, get some aquarium salt at your local fish store. Follow the instructions on the label. They may have a bacterial infection too. I don't know what's available in the fish stores where you live but if you can find something called "Maracyn Two" that would be a good one to try. If you live where antibiotics are not allowed except by a licensed physician or veterinarian you would have to try another product instead. Look and see what's available for bacterial infections in fish. Melafix is readily available in many places and is a natural antibiotic but it isn't very strong. Just do what you can and make VERY frequent water changes while they are sick. Clean water boosts the immune system and reduces the ammonia and nitrite too.

I hope they feel better soon...

At Your Service;
Chris Robbins