They seem to have a good response to food, all 7 of them are always keen to come out and investigate food. In fact, I only ever put the light one to watch them as they feed and they will now come out as soon as the light goes on even in the absence of food.
But it's harder to establish of all of them are actually eating the food, or if they are just spitting it back out etc. There are some that are obviously smaller than others but then from their patterning, they are also younger, or at least not as developed. So I don't know for sure, as I say there is definitely some evidence of white faeces along side regular coloured ones which sort of suggests there may be some hidden nasties.
I think, having thought long and hard, I'm going to stick with the dosage suggested on the wormer bottle for my tank volume, but rather than follow their dosing routine, which is once a week for up to 4 weeks. Follow the advice in the article that TTA linked and do a large water change and dose again 3 days after the initial dose and not dose again unless there are symptoms suggesting it is necessary.