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  鲜花(0 )   鸡蛋(0 ) | 
| It might be ick, an infection of the parasite Ichtyopthirius. . U& Z6 X& t, K8 N& o: S
 c# K# w% R. j; o- SYou can increase the water temp up to ~28C and give them drugs (basically Cu2+ ions), plus large quantity of water change. Google for further details.1 `% }9 A* R' X2 k
 
 5 V) P" j* i0 M) l. F5 _. V# h5 nIt might be hard to keep all the infected fishes, but treatment is necessary to protect uninfected ones.
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 ! A# C, d+ U& A- k! w8 @By the way, is it necessary to have >20C for koi and goldfish?
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