My 180g has ich, my 29g does not.
I QT'd every single fish that went into my 180g tank, and went fallow. Main cause was velvet, but the treatment is still the same. I treated for everything. Had some losses in QT as well as it's not easy to do.
Still somehow ich managed to find it's way in my tank. I haven't tried herbtana specifically, but I've tried others. None of them work. The only reason they are on the market at all and the only reason some people claim it works is because they do not understand the life cycle.
I mean by the time the white dots appear, it's pretty much over in terms of what you'll see. So they "fall off" naturally, people say oh well I just dosed this product last week, that much be the reason why they "fell off". And then due to the longer life cycle of the ich, a month later they think they are cured. But that's not the case.
Also, the white spots are a result of the fishes immune system, it is not the actual parasite. The parasite is burrowed in the fishes skin and the white spots are pus pockets. The parasite itself "falls off" for the next part of the life cycle, then the fish heals up. Fish heal really quick, so it's like they disappeared.
Things like cleaner shrimp and cleaner wrasse can help a little, but only if the fish will let them. Not all of them do. My diamond goby loves to get cleaned by the cleaner shrimp, he'll open his gills real wide while the shrimp goes to town. Other fish will immediately run away.
Another factor is the thickness of the fishes slime coat or something. Some fish rarely show symptoms, while others have multiple dots. I've never once seen my Naso tang scratch or have a dot on him. Meanwhile, my blue tang will have multiple dots sometimes. My mimic tang I will see scratching from time to time, yet I never see dots. Same for my cleaner wrasse, I'll see him scratch, but never dots.
Some people attribute this to immune systems, but I'm not sure I buy that. Because I've had these fish for about a year and a half and their immune systems are apparently exactly the same. I'm not sure my blue tang is every going to develop an immune system that deals with these things better. I hope he does, but I think it's just that his slime coat is really thin while the naso's is not.
My cardinals I've never seen scratch or have a dot on them. Same for the watchman goby. Velvet was another story, it got everything previously.
So ich management for me. I'd love to get it out of the tank, but it's not realistic as I could never catch my fish. And since I did it before and got ich anyway, It makes me less likely to tear things down. UV light + healthy/happy unstressed fish is how I deal with it.