ph - 7.4
ammonia - 0
nitrite - 0
i have a 350 litre trigon 350 jewel aquariam with jumbo filter.
stocking a variety of cold water fancy fantails 3 plecs and a golden weather loach.

last week i noticed a cotton wool type small ball on one of them which dropped off and no marks were left at all on the fish.

however this week one of my albino goldfish is now sitting on the bottom of the tank he is still eating when fed but is looking thin and very lethargic. he is fast losing his scales and has a few small red patches appearing. all other fish look fine. i have checked for worms, ich and lice and there is nothing at all. I have not tried any medications yet. I have done nothing different to the tank of late and carry out 20-30% water changes every 2weeks. my instincts are telling me that this is a bacterial infection but has set in very quickly within 24hours.

No new fish have been added to the tank since October 2004. Any suggestions.

They are fed a mixed diet of flaked food and frozen bloodworm and daphnia.

Please help.

Cheers M.

Hi there.

We'll do our best to help you figure this out but I think there's a little bit more info needed to figure out the source of the possible bacterial infection.


Firstly, are you familiar with the nitrification cycle and its end product, nitrAtes? As you may have read, nitrates cannot be filtered out, nor can they evaporate. The only practical way to remove nitrAtes from the tankwater is to perform waterchanges as dictated by the results on nitrAte test kits. NitrAtes have a toxicity level at or around 40-50ppm and anything higher than that for too long can cause serious health problems. It is best to keep them 40ppm or under. They may not appear right away, but if a high level of nitrAtes isn't eventually quelled, you can bet someone in the tank will feel the affects. Some sooner than others. Because you have not listed a result for a nitrAte test kit, I can only assume that you don't have the kit for it and don't know the level your tanks water is at. Without knowing what the nitrate level is at, you can't know how much water you should be changing weekly. This I fear may be the reason why you are seeing problems starting in your tank.

In a high nitrAte setting goldfish immune systems are compromised and this allows all types of bacteria, fungus and parasites a good foot in the door for infiltration. This may be the reason why you saw a spot of fungus on one of them.

So, with this in mind, here's your best course of action so far:

If your pH out of the tap closely resembles the pH in your tank (within 1ppm) you should perform a 50% waterchange once a day for 3 days. In this time frame, you should go to the store and buy yourself a nitrAte test kit and test your tankwater. It would actually help to get the kit and test before you change some water but I think your fish need the water to be freshened up ASAP.

By the way, how many fish do you have in the tank and how big are they (each)?

How many gallons per hour is your filter rated at and do you keep it on full flow?

And how about the fuzzy spot, did you actually see it fall off???


Post back soon!

One more thing that pops to mind while reading the post 350 gl is roughly a little less than 90 US gallon. How many goldfish exactly are in the tank? And when you say pleco, what kind?
The thing is, a pleco likes to snack on a goldfish's slime coat, especially if the fish isn't moving much. When you say the fish loses scales, did he do that before he started resting a lot, or did that start afterwards?
My thinking is that the plecos are responsible for the lost scales, and the red patches are bacterial problems due to the eaten away slime coat. A slime coat is a protective coat around the fish, it keeps away parasites and harmful bacteria. When the slime coat is compromised, then the fish has lost his protection against parasites and bacteria.

IMHO, Ranchugirl I think has hit the nail on the head here, personally I would remove the pleco.

Goldies like vegies also.

Hmmmm. I must be slipping, I didn't catch the pleco being in there. That would have been my first thought. I've seen plecos do exactly as Ranchugirl described and the end product was not a good one........