Test Kits - Use by date?!

[WarChild]

Hi There..
I've had a green party tester for almost a year now, and it seems that it doesn't work as well as it use to? I've used about half the bottle, and the reactions are nowhere near as strong or quick as a friend who just bought an e-z test?
Thanks in advance.

 

[johnboy]

it depends on a lot of things, but a year seems too long to be hanging on to one... i'd be buying a new one if i was you... hopefully from the banner ad above, which donates some of the money to help bluelight...
keeping it in a cool, dark place can extend there loves... the newer ones in glass bottles dont have to be kept in the fridge any more, but it could lengthen their usefullness if you do

 

[aj]

In the end everything goes bad.
It is not the liquid that goes bad but sooner or later, the reagent does 'something' to the dropper.
We place bottles upside down, so the reagent actually has contact with the bottle (in order to test it) and we leave it there for months. Some bottle/dripper combinations stay clear for ages, some get a little brownish teint (is that the word?) after a while (but definitely not the spoiled dark brown/almost black that we saw with the small test kits).
The reaction is still, as the previous poster also states, OK but looses intensity.
We have tried many different bottles plus drippers, all are still standing upside down in the lab and our conclusion is that any test kit (not just ours) will get this brownish teint after a few months but they are still reliable.
aj