KIRSTYANNE wrote:

I am not sure on how you test for Ammonia, Nitrite and Nitrate but I
have tested the PH of the water which was 7.2. The tank we have at the
moment holds just over 20 gallons but I have just purchased a Juwel
Vision 180 which holds 180 litres. They are not in the new tank as yet
as I am currently treating them with an anti-bacterial remedy.

Kirsty,

You will need to buy test kits to test these. It is very important to
do this from time to time, especially when problems are occuring.
Sometimes you can take water samples to your local fish shop and
they will do a test for you.