Test Kits - Help!

Hey everyone,

I wanted to ask a question about different test kits that are out on the market. The reason I am asking is that the other day I tested some parameters from my aquaruim. These were the results:

Ammonia-0
Nitrite-0
Nitrate-0
Calcium-420
Alk-8.4
PH-8.2
Phosphate-0

Since I had to go to the LPS to get a new Alk test kit I decided to take a sample of my aquarium water and see if they get the same readings. My LPS offers free testing. When the guy was done with his testing, he found that my all of my pararmeters matched my readings, except the Calcium. He read the calcium at 300ppm instead of the 420ppm that I read just 2 hours before.
He used Salifert test kit and I used API test kit. He told me that Salifert test kits are better and more accurate then the API. I bought the salifert test kit and ran a test on my brother in-laws tank, he tested his calcium that same morning . He uses API also, and he tested at 460ppm, but when I used the salifert on his aquarium water I read 300ppm. He has an established tank 2 yrs in the making and it looks pretty good.

At this point I don't know which is more accurate, I've been using API for a long while and it seemed good to me at the time, but now, I just don't know which Test kit to trust. Can someone tell me which one of the 2 test kits I have is better?, and why did the test kits show different readings?. any info is appreciated, thanks.

 

I have API also and for a long while mine has tested from 540ppm to 600ppm, so
i am goin to keep an eye on this thread because api is all that I have used since i started
checking for CA, and I'd like to find out.

 

That's a pretty big difference in Ca levels. Make sure you are following directions exacty on both. Check the API kit to see if it is out of date - There was a recent post on the lot #s on the API kits that indicated their date of manufacture and how long they were good for until they expire.

Here it is:
http://www.3reef.com/forums/water-chemistry/those-who-use-api-test-kits-fyi-48335.html

 

mine is good till 11/08, yeah i read the post, now lets see if Tyslin did, i am very curious
about this one

 

Hey guys,

Thanks for the replies, and I thought the same thing maybe my API test kit is expired or that I just bought a bad test kit. I tried looking for the Expiration date but couldn't find any, I did see a Lot# though, thanks for the link BOGIE really helpful, I will check my test kit today. I will also do another test with both test kits, to verify that I am doing the tests correctly.

 

There has been some concern(issues) about Saliferts test kits lately. I also use API test kits and I think that at this point, I would follow the Api test kits. If you really want to kill your doubt, get another name brand test kit and see how that comes out. Luna

 

Ok I checked the Exp date on my API calcium test kit and the last 4 digits are as follows: Bottle #1 1207,..bottle #2 0208. They are both 6 months or less from manufacturing, so they are good test kits. By the way,.. and it was my mistake, I have a Seachems test kit not salifert, sorry about that guys. I again decided to go to a different LFS and had them check my water yesterday (they used RedSea test kit) they read my calcium at 360 ppm closer to the seachems test results then the API. I then went home and took my time reading the instructions on both the API and Seachems test kits. I followed the instructions to the T, and got these results. API calcium was 420ppm, Seachems Calcium was 360ppm. any thoughts and opinions are welcomed.

 

wow thats a pretty significant diff.
I also use api. seems to be the one all my local lfs recommend.
guess i will be watching this one to see whats the diff. is with the test kits.
i have been keeping my cal around 420 according to the api kits.
getting ready to keep some corals in the neer future and like to look of coraline on the rocks. ( which seems to be increasing daily)

 

60 ppm's is a big diff. All the LFS that I have visited that check your water for free, uses API. If you think about it, thats not a good sign, b/c they're not going to use the most expensive one which would be the best kits. So in summary, maybe API isnt the best out there. Im going to start switching out API for something else, maybe Elos(have heard good things, Otty)
If you want to kill the doubt, either borrow a friends kit or buy another good name brand kit. Just a thought, Luna

 

Im hoping I can shed some light on this, hopefully. I use the API marine test kit, don't have the reef one yet. If you read the instructions carefully for the nitrite and nitrate tests it says that...
Nitrite: "This test kit reads total nitrite (NO2-) level in parts per million which are equivalent to milligrams per liter from 0 ppm to 5.0 ppm. (Other nitrite tests that measure 'nitrite-nitrogen' (NO2N-) will give readings 3.3 times LESS than this test kit.)

The nitrate says 4.4 times less.
Thus, I would make sure that each of these test kits is measuring the same thing before you can compare them. I know this isn't the calcium test, but those who have it see if it says anything similar.