Disease

There's no where else to ask this so thought you people would know anyway...
I have Siamese Fighting fish... (well my mum does) only had them a week...
They are in separate tanks but they both appear to have the same problem.
They have kind og weird fungus growing on them... it looks like white cotton
wool hanging off them....
And their colours are going quite dull...
So yeah, they're not that healthy :) Anyone know what this is??

Thanks