The TetraPond Range of Pond Water Test Kits
Testing your water is extremely important.
The water parameters in your pond can change over night - be aware of this if
you don't want to go down to the pond to feed the fish etc and find
that you have a major problem on your hands .. make it a rule, even
if you believe that all is well - to test your water on a regular
basis .. that way you will be alerted to any changes as they
actually happen and be in a position to do something about