If you have scaleless fish be careful using a lot of ich meds because in the fine print, many say "do not use on scaleless fish".
Even if it doesn't say it, most will tell you to use 1/2 dose. Same with salt.
HOWEVER, there is a med that I would recommend because another fishkeeper used it and it worked wonders. I tried it and it worked too. Its called Ich Attack by Kordon. It mentions that its organic and will not hurt your fish. I tried it myself and it really works. Me and that other fishkeeper tried double dose and it cleared the ich. I tried normal dose and didn't see good results but the doube dose worked perfectly. I used this on my catfish.
I have tried Quick Cure and Rid Ich and would not use them on catfish. When I used the Quick Cure, my catfish started acting funny so I quickly did a 75% water change and put carbon in. For Rid Ich, you have to dose 1/2 strength because my cats did not act right when I used full dose.
Ich Attack is the only one that my cats responded to ok and even at double dose which helped cure the ich, my catfish are ok.