white spots

I have finished the |Interpet treatment for whitespot but my molly still has white spots and doesn't look well as the others.

It has 2 spots on its side and one by its tail. They are small and a bit fluffy looking but not mega so. A mate described it as a tiny bit of mashed potato!

Im thinking it wasnt ich after all but what else could it be and what should I do about it. will the ich meds have done the other fish any harm?

Well Ich are small discrete spots like salt or sugar grains. What you're describing sounds like a fungal growth or maybe even columnaris tbh. However you need to be fairly sure of the diagnosis before adding any other meds. to the tank. Maybe google for photos of those and see if you find anything that matches.

There's a reasonably decent pic of columnaris in the fish disease section - might be worth having a look.

I suppose that could be it but smaller than that. Would I be able to put this fish in a small seperate tank even if it wasnt cycled?

Just wondering if I should get it seperated so whatever it is doesnt spread but would I run into problems with the water?

You could do that jammy, all you would have to do is check the water daily in case you have any problems. As it is only 1 fish there shouldnt be too many problems and it would be better to do that than risk infecting your whole tank.

You could pop some gunk from your current filter into the other tank.

Try and get some pics so we can work out what it is. Finish the white spot treatment though, as you never know