Tester Kits?

[evilchild]

i have the liquid tetra testing kit thats test almost every thing. pH GH KH NO2 NO3
do these have a shelf life? (dose it go out of date?) if so how would this effect the out come of the tests?

 

[xxBarneyxx]

Yeah they do have use by dates. Not sure how long they are good for (it varies from kit to kit) but when they are out of date they can give false readings (either to high or too low), not work at all or still work perfectly fine (I have used some test kits that where a couple of years old and they gave the same readings as a new one).

 

[evilchild]

think i better have a read on the box then, just to play safe. thanks