My 55 has ich but i started using seachems polyguard, I think that a mistake.

[poor little fish]

My 55 and my 40 have ich. I called my local aquarium store and they suggested that I use seachem's  ployguard. I used it and it seems weak. I have ich-x and want to change over to that. However, seachem has that sulfathiazone in it. I says on the ich-x bottle not to use with other meds especially those with sulfa. I treated my 40 first and lost 3 angelfish and I was warned that the med would turn my water blue, it never did. Somehow I cross-contaminated my 55. My favorite fish are in that 55. They clearly have ich and I've treated with salt and an airstone and temperature raise. Should I change over to ich-x and how would I do that safely. Would i do a massive water change after filtering with carbon. Then add more salt and the new meds?

[Fish Folk]

Bummer! I'd defer to others on this, but if it were me, maybe move fish over to a quarantine tank (if you've got one) and treat them in there with Ich-X. Ich transfers from wet hands, wet nets, etc. When treating in an established aquarium, the gravel should be vac-ed because the ich tomites get down in there. But then you've got the potential of cross contamination with your water changing equipment (python, etc). SO, if  you do a big water change, keep that in mind. 

Raising heat a little speeds up the Ich life cycle. Ich-X can work exactly as described. Yes, carbon to remove the previous meds, and a huge water change would be important. However, bear in mind that the more you do huge moves with water changes, etc, the more potential stress you're placing on your fish. It's really a terrible challenge . . . 

[Colu]

You could do 50% water change and run actived carbon for 24hour after 24h remove carbon and start treatment with ich x