Disagree. I think misleading readers is far more unhelpful than is suggesting things that one reader may not be able to use. He is not the only person reading or learning from this thread.
It is helpful, IMO, to know he will NOT get "crystal clear water? I want my tank to look invisible" with means short of methods like ozone.
Once that is said (and no person before me mentioned ozone), then IMO, its fine to suggest other methods that may give a useful but not complete effect, but only IF you note that it isn't going to give what he specifically asked for.