For Nitrate, I've pretty much always used a Hagen kit because it tells me what I want to see :redface:. Also, I hate trying to get a LEVEL spoonful with other kits. Anyway, I've tossed the Hagen kit in the garbage and will try to use the other brands once again.

I've got a Salifert Nitrate Kit and an Elos Nitrate Kit. Both are within reasonable age. Just tested my FOWLR this AM with both. The Salifert showed a reading of 50+, while the Elos indicates 10 at the most.

Just wondering if anyone else has experienced this discrepancy?

Thanx much,

The Elos reagents are very sensitive to elevated temperatures. If they were stored above (I believe this number is correct) 25 degrees celsius then the reagents degrade and you get a more brownish color from the last reagent. This will cause low readings. Given some of the warm days we had this Summer I wouldn't be surprised if the temperatures of the reagents exceeded 28 degrees regularly. Check with Jesse on the Elos sponsor forum on RC for clarification about the storage temperature. It doesn't seem to get much discussion despite the fact that it destroys the test kit.

Thanx. That's probably it, then. It is a brownish/yellowy colour and my condo gets very hot. Damn. I was liking the result it was showing, hehe.