Malachite green

[i have crabs]

i dont think matchlite is a good way to deal with the problem thier is a good chance youl od and kill him tangs dont cope with matchlite well,if hes really covered i might help him long enough for a real treatment to start working but it might just stress him out and make it worse i would recomend copper but you need to have a qt tank you can devote only to fish,buying a 67g qt tank to use copper was the best thing i have done to prevent serious problems in any of my main tanks.