What is the lifespan of test kits?

[Argentis]

Hi, I was wondering if anyone could tell me what the typical lifespan of test kits? Mine are about 3 years old, and I'm getting a new tank going. The tank has been running for about 2 weeks, and I'm not seeing any change on my ammonia, nitrite, and nitrate tests. The one exception was a nitrite blip of 0.25 ppm for one day, and that was about a week ago. I have not seen any ammonia, and nitrates are holding steady at around 7 ppm. I'm also wondering if I'm going to see a cycle at all, since this tank has been running for about 2 years since my 60g sprung a leak, and I moved everyone into the 20g (the 60g wasn't too heavily stocked at the time). Over time, the fish have died, and my last fish from that tank, an SAE died around the 20th of January, and then I rinsed out the tank (not the filter or gravel), and relocated and set up the tank again.

I've got 4 swordtails in the tank, and I'm not sure if I should be seeing something, or if my kits are messed up, or if I won't see a cycle at all. I kind of doubt it's the last option, since I'd think the nitrates would be rising in a cycled tank, and they're not.

Any help and input would be much appreciated.

Argentis

[Qattarra]

IMO , get new kits. I think you wont want to miss any spikes building.

[Argentis]

Thanks for the reply. Are there any brands to try and get? or avoid? The kit I have is the Nutrafin FW master kit. I did see that Pisces has the API FW master kit on sale this month. I'll probably get that unless there's an overwhelming reason not to.

[Toirtis]

I like the API kits for ease of use, and they are quite decently accurate....price is good, and they include a decent amount of reagent, too. The API Master has ammonia, nitrite, nitrate and pH, which is a good core set of tests to have.....for whatever reason, the Nutrafin Mini-Master lacks the nitrate and has a hardness test instead....the Nutrafin Master has everything, but is reasonably spendy (usually about $75+).