i dont know specificaly about interpet antifungus by i know that 'waterlife' protozin treats whitespot & fungus so its possible that a fungus treatment treats whitespot. and i believe raising the temp does help.
search for the white spot (ich) cycle and got to your lfs to buy some treatment for...
you could have i would say up to 15 as long a nitrifying bacteria is present in the filter to cope with the amonia made through decaying organic matter. they should shoal fine in a 10g tank.
