please help fish sitter over fead my tank

[intarsiabox]

When I go on holidays I pre-measure my daily food rations into an ice cube tray for my fish sitter. This way I can still control the amount of food given when I'm away and don't have to worry about over feeding.

I agree that a Tetra kit may not be the most reliable. Try testing a newly mixed batch of salt water and see if the Tetra kit reads close to zero for nitrates, if it is still showing 50ppm then you know your kit should be thrown out.