It may well be an idea your Mum buy a book on fish health so that your Mum better understands how to look after her fish as there is lots to learn about keeping them alive nd well .
Did you know that if properly looked after goldfish can live up to 40 years , koi can and do live in excess of 80 years we have one koi 24" who is this year 28 years old .
The book I suggest you buy is this The Manual of Fish Health ISBN 0861013869. Dr Chris Andrews Adrian Exell, Dr Neville Carrington.
This is a very good starting out book that teaches you everything you need t know about keeping your fish healthy you can get them for next to nothing on Amazon
We hope this helps you both grow into the hobby
Dave
Did you know that if properly looked after goldfish can live up to 40 years , koi can and do live in excess of 80 years we have one koi 24" who is this year 28 years old .
The book I suggest you buy is this The Manual of Fish Health ISBN 0861013869. Dr Chris Andrews Adrian Exell, Dr Neville Carrington.
This is a very good starting out book that teaches you everything you need t know about keeping your fish healthy you can get them for next to nothing on Amazon
We hope this helps you both grow into the hobby
Dave