Jbl Test Kit Reliability

[Robj]

I've got a JBL liquid test kit covering all the normal measures.

I get consistent ammonia results, with only very small fluctuations. The nitrate results also seem fairly stable. Nitrites can be all over the place. I'm trying to work out if it's the test kit or if my nitrite levels really do fluctuate wildly. The fish all seem fine and the tank has been established and cycled since June.

 

[TheRedDarren]

I had the same thing with my API (I know, I know!!) test kit, all seemed well apart from the nitrites, but at least the fish got an extra water change from it!
JBL are a good brand though so I would be inclined to go with it..
I guess the thing to do would be to cross check it with another kit if you know another fishkeeper.