Sick green severums

[Martinj1972]

Please help me I've got two big green severums they are amazin one male one female. But the last 4 days they have been really under active and they have both got loads of white spot and have both turned really blackive put one lot of medication and got to put another lot in on Saturday. The thing that's puzzeling me more is the other 10 fish are fine plzzzzz someone help me I don't want to loose my two beauties

 

[jlk]

Hi! I dont personally keep these guys but some more information will help other members to better advise you on your situation. A pic of the spots & black areas will really help as well!

Tank size?
Tankmates? Are any new?
Water parameters (ammonia, nitrite, nitrate, ph)?
Water change schedule (%/#wk)?
Treatments used? Was the first med removed properly before adding the second?

Thanks!