There is probably nothing wrong with the salifert kit - I can't speak for it's accuracy as I've never seen or used it.
I would use them both and compare the readings.
THEN as a help to all the other fishy folk on here - you could report back to us on how you got on. Let us know so we will know how good it is in comparison!
If you need help with the API kit then just ask. I found it a bit tricky at first - getting false readings and I wasn't sure what I was looking for.
If in doubt you'd be best to check.
I'm glad I did.
