Test kit variations.

[spawn_e_git]

I have used Tetra test kit for No3 for a while now and when I test the water of my 40gal reef I always got a reading of 15-20ppm.
This always made me believe that the Aqua-Medic Nitrate reducer run on the tank was useless.
I then brought a Salifert No3 testkit and found the No3 level to be 0.5!!!
I took a water sample to my LFS and did the same tests with a Salifert and Tetra of theirs. The results were the same: 15-18 on Tetra and 0.5 on Salifert. The LFS said to beleive the Salifert. If this is true then I have been wrongly slagging off the Aqua-medic unit.
My LFS also did a comparison between a Salifert and a Tropic Marin on his water and they showed the same.
Has anybody else had the same sort of experience with test kits? Which one do I beleive?

Your thoughts please...........

 

[Anonymous]

When it comes to something as important as test kits, I believe that you get what you pay for. In my experience, the kits that utilize more complex titration methods tend to also be more expensive, but you can also be fairly confident that you're getting accurate results. I believe that Salifert is indeed a better/higher quality manufacturer, and I would tend to agree with your LFS. I'm also impressed that they are either using both kits, or are willing to crack open a new kit to help you with this. It speaks very well of their dedication to the hobby.

Other kits I happen to like are Seachem and LaMotte. However, it's been a few years since I've had my own sys to test, and at the aquarium we have a full lab (YEAH!) and a young woman dedicated to testing all sys's. Needless to say, we have access to chemicals and machinery/technology that the average hobbyist would not. Also, because I'm not a lab tech, I can watch while she does the testing, but I'm not usually allowed to perform any tests (it is her lab and all). I'm sure there are plenty of others who will have additionally helpful input.

You might also want to search our library at --> http://www.reefs.org/library/ although I haven't yet found anything specifically on test kits and testing. It's still worth a search, though.

OH! If you're having nitrate issues, are you using a refugium or deep sand bed? If so, could it be that they are not fully developed? If not, may I suggest you make the addition of something like that your next "to do" for your sys? If you're running one of those nitrate reduction methods, I'll suggest that you give it time to "kick in" before resorting to chemical filtration methods.

I hope this has been somewhat helpful.

 

[sambryce]

My Salifert nitrate test kit consistantly reads lower than the Aquarium Pharmaceuticals test. Something like the AP test would show 15-20ppm when the Salifert test showed about 3ppm. I always trust the Salifert. Salifert has much better resolution in the low range than most popular testkits. All the other AP kits (NH4, NO2, etc) read very close to Salifert.

 

[spawn_e_git]

Thanks for the replies.

What I am trying to find out is why there is so much difference. For every person who says that the most expensive are usually the best, there will be another person who that is not always the case.

I'm going to go to a few LFS's this weekend and get them to test my water and see what results they get with their test kit and make a note of them.

There is a guy from Salifert who replies to posts on ReefCentral. He is looking at the Salifert batch numbers on my testkit for me to see if there was a problems with them. He seems very constructive rather than just saying that Tetra are **** and his are the best.

With regard to the Nitrate reducer. I got it for a FO tank I have but it wasn't much use so I put it on the reef rather than through £500 of kit in the trash.

 

[Anonymous]

I never said Tetra was crap, that's your own inference.

However, one way to keep test kit costs down is to use different reagents. Get yourself a science lab supply catalog, and your jaw will DROP when you see what quality products run. Consistency in manufacture is another measure of quality, in my opinion.

 

[spawn_e_git]

seamaiden

I did not imply that you said the Tetra kit was crap but that the guy from Salifert did not say the Tetra kit was crap.

Have you any links to these catalog?

 

[Anonymous]

No, as far as I know, you have to actually be a certified scientific laboratory to have access to these products (especially now, especially in the U.S.). The catalog I saw was hardcopy, and hardcover! (Yeah! It was that big.)

Sorry for the misunderstanding, no hard feelings, eh?

I hope you get it sorted soon enough.

 

[brewerbob]

Do some research and find the chemicals required for the titration. Then look in the phone book for chemical suppliers. I don't think you'd need anythign special to order the stuff.

There are catalogs that supply such stuff to businesses, labs, etc. I can't for the life of me remember any of the names. I will ask around and get back to you.