dd's goldfish looks a bit poorly - any advice?

[3littlefrogs]

My 8yr old's gold fish doesn't look too well. Today is my day off and I need to do something as she will be really upset if she comes home from school and it has pegged out.

We cleaned the filter and replaced 25% of the water yesterday as per instructions from pet shop. She has been feeding it as instructed and I am not sure what else to do.

Only had it 6 weeks - any goldfish gurus out there?

How did you clean the filter? With tapwater or water from the tank? If you used tapwater, the chlorine will have killed off all the good bacteria that cleans up the poop in the water.
Did you use dechlorinator when you changed the water?
When was the last time you changed the water?
If over a week ago, change some more - at least 25% again, and don't forget to add dechlorinator.

Thanks so much for responding so quickly Gb. I used a bowl of the tank water to clean the filter, then discarded it. Reassembled filter and put it back.

Yes, I used the dechlorinator - filled a clean bowl the day before, added the DChl. and left it to come to room temp, then used that to top up the tank. That was yesterday morning.

The thing is, the walls of the tank look a little bit "scummy", but filter was quite dirty so seems to be working. It is bubbling away at the moment.

The fish is just sitting quietly at the bottom of the tank, and wasn't very interested in his breakfast this morning.

I am just worried because she is going to be terribly upset if anything happens to him.

We put some oxygenating plants in the tank, on the advice of the shop, but had to take some out yesterday because they didn't look healthy. Could that be related??

scummy walls not a problem - it is just algae. You can use a clean plastic scourer or buy a magnetic algae scraper to clean it off.
Good that you did exactly the right thing regarding cleaning the filter and adding dechlorinator.
I am a bit more concerned that the tank is new - only set up for 6 weeks. Do you know what 'cycling a tank' means? You need to build up the bacteria on the filter that will keep the water clean - the filter acts as a bed for the bacteria - they convert harmful ammonia (from fish poop and wee) into slightly less harmful nitrites and then into much less harmful nitrates.
Do you have a test kit? You need to make sure the ammonia and nitrite levels are not too high to be poisoning the fish.

Oh, and the oxygenating plants are a good idea - long strands of ELODEA are what you need - goldfish like to nibble them too.

Flush it down the loo and get another goldfish?

Will buy a test kit today. Thanks so much for the advice.

Callisto - you cruel thing!!! He is actually swishing his tail - just not as lively as usual. So not at the flushing down the loo stage yet, I hope.

I can think of dozens of things to do on my one day off, other than faffing with a goldfish, but dd is very fond of him. so will go to the pet shop now.