Hi all, Can anyone give me tips on how to keep Pearlscale Goldfish healthy?? We have bought 8 pearlscale goldfish but all died in less than a week. And bought another 6 pearlscale goldfish and died 5 in a week. They all died with Whitespots. How to prevent the Whitespots? We've treated them but still they died

. Poor little fishes

(! Now, I have only one left, and I hope she will live long. The picture attached is the only one remaining Pearlscale that is still alive. Can anyone give me tips?? Thank you!
My aquarium tank is about 10 gallon. The tank is bought on February 6, 2010.