Test Kit Expiration

[new2reef]

I use an API Test Kit - have the Saltwater and Master Reef. Mainly use the Saltwater. For the last couple months, the Nitrates have been running between 2 and 5 ppm. Yes, it should be zero, but I know I feed a bit too much - newbie still learning.

 

Recently, the Nitrates shot up to 15-20! I did have a brief GHA attack a month ago, but tank actually has less algae on rocks and glass now. The sudden rise puzzled me and was after the GHA was gone. Even tested LFS saltwater, which showed some Nitrates (2-4 ppm)! All fish, coral and inverts are healthy and happy.

 

Then I decided to use the new Master Reef kit and Nitrates are 5 ppm. No water change in the last 24 hrs, so no reason for the sudden drop, unless the solution has gone bad.

 

So, does the solution go bad over time? How long will kit last? Had the Saltwater kit about 6 months? Does heat affect the solution? Had kits in the laundry room and week ago noticed the vent was closed - no wonder the room was always warm!

 

Any thoughts?

[bdare]

It's hard to say how long they last because they don't have an expiration sticker, but API is known to have a short shelf life.

[new2reef]

When you say short - and I know you are just giving a general timeframe - are you thinking 3 months, 6 months, a year? Have you heard of heat affecting the solution too?

 

This would explain the descrepency in results.

[tinyreef]

some kits have expiration dates or shelf-lives. ime, this is usually a couple of years though (from the manufactured date).

 

some reagents or methods are affected by O2 exposure. some by sunlight/UV(?). it'll usually depend on the time from first opening the reagent bottle though. i.e. if you first opened the bottle 14-months ago but never used it, chances are it's toward the end of its shelf-life. otoh, if you merely bought it 14-months ago and never opened it, the shelf-life span would not be as far along.

[new2reef]

Update on my "bad" solution.

 

I think my Nitrate solution was bad. Saltwater kit was bought off the shelf, so who knows how long it was there. I had to wait for LFS to order Master Reef. SW kit was showing Nitrate of 20 ppm, while MR is showing under 2ppm.

 

I knew the reading was bad, because the fish and corals are very healthy, coraline growth taking off and my algae problems are going away - was having to clean glass everyday, now it's once a week! But my Nitrate readings were going up, as algae was disappearing!

 

One thing I noticed with the SW Nitrate #2 was the solution was hard to get out and dropper would clog often. With MR #2, it drops out freely, just like the others. Solution had gone bad.

 

I've kept my feeding and water changes constant.

 

Be careful with old kits (less than a yr old) - it's better to toss it and spent the money on a new one, than risk hundreds dollars or more of livestock!

[hooligan_78]

They do tell you to shake that bottle for at least 30 seconds though. Must be some thick solution.

[Jakesaw]

I was looking for this info a few months back - and I found the API Marine test kits had a 1 year shelf life.

[new2reef]

Problem is you never know how long it's been on the LFS shelf! I suspect my Saltwater kit was sitting around 6 months.

 

I always shook Nitrate #2 for 30 seconds. My old solution would plug up after 2 to 4 drops, then I'd have to clear it. All others just flowed easily. My new solution flows like the rest - never plugs! Lesson learned.