We've recently (about two weeks ago) bought a new fish tenk (+/- 20 Litres) with 8 small goldfish. We're totally new to the goldfish hobby and have no knowledge óf keeping them whatsoever. The owner of the pet shop said we could keep 5 big goldfish and 5 smaller goldfish. We, however, chose to start with 8. Two bigger ones (about 7cm) and 6 smaller ones (about 5cm). After 2 days, one of the two bigger goldfish started to get sick. I went to the pet store for some advice and they said I must feed them less and do a water change. We changed about 75% of the water and I started to only feed them late afternoon, once a day. After 3 days from purchasing the goldfish, the sick one died. I bought a bigger filter and a floresent light. Now it seems one of my smaller fish has ick. I researhed, but isn't sure. Why is this happening? Please give advice on keeping and treating sick goldfish and feeding and cleaning the tank and filter! How can I better the condition of the tank and fish.

Please help, any advice will mean the world to me!!

Thanks in advance.

When you first got the tank you should have filled it and left the pump an filters running for at least four days before adding the fish. Also when you bring the fish home from the store in their plastic bag, you should put the whole bag in the tank with the water and the fish in so they get used to the difference in temperatures gradually otherwise they have a body shock going from one extreme to the other. I recommend at least an hour or two before splitting the bag they came in and letting them out. Also feed them twice a day once with 12 pinch of flake food and once in the evening with blood worm available from your pet shop. Hope this helps

I'm not great with the metric system, but is your tank about 5 gallons of water?
If so, that's not even enough water or space for 1 small goldfish.

You were unfortunately misinformed by the pet shop.

Please let me know if this is the case and I'll do my best to try and help
With your tank situation.