I have a new black and gold (looks more like bronze) fantail. He/she is excellent in colour. He is in a tank with two other fish (a small bristol shubunkin and a comet). The three of them get a long totally fine. They are both about 6 months old. The fantails age I dont knwo but Ive only had him two weeks. he came form an excellent and very reptuable fish supplier. He swims about fine, visllay very healthy but def constipated. Im very clear on what I need to do to help resolve this but my question is how do I deal with the other two fish? If I stop feeding the fantail etc then how do I feed the other two or will they be fine effectivley being unfed while I just proceed with the 'treatment' of peas and epsom salts?

just feed it mashed peas... the peas don;t hurt anyone else in the tank and will actually clear their systems out along with your ill fish. make sure you dont over-feed and let your filter get clogged though-check your system every day and wash it if its dirty and green with pea-stuff.

Go with peas and vegetables for all of them! It won't hurt anyone, on the contrary, it would only clear out the system of all your fish which is only good for them. If my fish would be constipated I would treat him this way (:

You can start feeding them normally again as soon as your sick fish is healthy!

Good luck : D