Do water-test chemicals expire?

[CaysE]

I'm somewhat weirded out... I have an older API freshwater master test kit, before they added the nitrate tester, and the hardness test simly told you if the water was soft, hard or somewhere inbetween. I recently bought new nitrate and GH/KH liquid testers, but I'm confused with the results.

Some background: I have a 20 gallon tall tank that's been set up for a few weeks now, maybe close to a month. It has a Flourite substrate, CO2, AquaClear 50 with a prefilter on the intake, heated to ~79 (up to 83 today no thanks to the heat wave), driftwood, a number of plants (wisteria, ludwigia, rotala, java moss, blyxa japonica, dwarf lily), 8 harlequin rasboras, 2 otos, and a goby.

Here's the confusion. With the old test kit, I'm getting a ph of 6.8 and then zero across the board for nitrites, ammonia, and chlorine. But my brand new nitrate tester is also showing zero. Something can't be right with that, right? And in case anyone was wondering, KH is at 2 degrees and GH is at 4.

So what's wrong here? I should be showing something on Nitrite, Ammonia or Nitrates, correct? I find it hard to believe my specs are perfectly in balance.

 

[neoginn]

Hi I recently had that question too, and I found out that yes indeed the chemical testers do expire. I have no idea why.

 

[joannde]

I've bottomed out on nitrates in a 10G tank that has 4 bettas (divided tank). My tap water tests at 5ppm for nitrates and I expected my tank to be the same (I'm having to do near daily 25% water changes since one of the bettas ripped most of his dorsal fin off - its growing back and I want to make sure he has great water so he doesn't end up with an infection). When I saw BGA/cyanobacteria growing I tested the tank for nitrates and found them at 0. And all I have in there are four TEENY java ferns and four small (1/2 golf ball, compressed) clumps of java moss.

Be VERY careful with 0 nitrates - BGA is a real risk (as I found out !). I'm now dosing NO3 to keep the BGA in check while I continually clean it out.

 

[greenmaji]

One year after you open the bottle is the going info on the subject last time I checked.

joannde.. planted tanks are a whole new ballgame, thats why there is a form dedicated to that subject Any plants pretty much changes what water peramiters are exceptable. (kind of like a fish only vs a reef tank with SW)

 

[Jchillin]

Another thing to consider is the shelf life. I had the opportunity of purchasing a gh/kh test kit. My test results were absolutely horrible. When I checked the expiration date on the bottle, it had expired two years ago (Aquarium Pharmaceuticals purchased from Petland Discounts).

Petland exchanged the test kit and the new one provided results that made sense. I don't know what the shelf life is, but I would suggest checking the expiration date on all test kits.

 

[Caincando1]

I have an old(1998 or 1999) tetra test kit that is spot on to my brand new API master kit and junlge test strips. I was afraid the old one was bad so I bought a new one. I was amazed to see how accurate it still was after all these years.

 

[CaysE]

Just for kicks I bought a new Ammonia tester, figuring that this would be the most important to know. It still reads zero. Brand new Nitrate tester read zero. So unless my Nitrite tester is off, I should probably just consider myself really lucky.