# ACCURATE test kits?



## Bavarian3 (Oct 21, 2004)

hey guys, i use an aquarium pharm. test kit and i feel its not accurate, my lfs tested my tap PH at 7.8 and i tested it at 7.4. I also am in need of a phosphate test kit do u guys have any recommendations for that? What other test kits should i get? right now i only have nitrate, nitrite, ammonia, PH.


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## Darkblade48 (Nov 14, 2004)

If you inject CO2, the discrepancy between your and the LFS' results may be due to the fact that the CO2 is gassing out, causing the LFS reading to be slightly higher than the one you take at home.

Also, if you want accurate test kits (and are willing to pay), then LaMotte test kits are great. I've also heard that Hach makes good, reliable test kits as well


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## TWood (Dec 9, 2004)

Bavarian3 said:


> I also am in need of a phosphate test kit do u guys have any recommendations for that?


http://www.thatpetplace.com/Product...Kits/T1/F73+1044+0402/EDP/43949/Itemdy00.aspx


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## Bavarian3 (Oct 21, 2004)

Darkblade48 said:


> If you inject CO2, the discrepancy between your and the LFS' results may be due to the fact that the CO2 is gassing out, causing the LFS reading to be slightly higher than the one you take at home.
> 
> Also, if you want accurate test kits (and are willing to pay), then LaMotte test kits are great. I've also heard that Hach makes good, reliable test kits as well


LaMatte is more than im willing to pay. Just cant justify spending that much for a test kit. My tank is non co2 injected so yeah i dont know what the deal is.


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## Bavarian3 (Oct 21, 2004)

TWood said:


> http://www.thatpetplace.com/Product...Kits/T1/F73+1044+0402/EDP/43949/Itemdy00.aspx


never seent his website but they sure have alot of stuff! i came across the hagen test kits they seem to be good prices how are they?


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## gnatster (Mar 6, 2004)

That Pet Place aka That Fish Place is sorta local to me, been shopping there for 30 odd years.


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## TWood (Dec 9, 2004)

Bavarian3 said:


> never seent his website but they sure have alot of stuff! i came across the hagen test kits they seem to be good prices how are they?


Dunno, I use and like the AP kits.

TW


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## trenac (Jul 16, 2004)

Bavarian3 said:


> hey guys, i use an aquarium pharm. test kit and i feel its not accurate, my lfs tested my tap PH at 7.8 and i tested it at 7.4. I also am in need of a phosphate test kit do u guys have any recommendations for that? What other test kits should i get? right now i only have nitrate, nitrite, ammonia, PH.


 The test kits you will need for a planted tank besides the ones you have are KH & GH. For the general test like PH, KH, GH about any brand will work: TetraTest, AP, RedSea etc.. For test kits like N03 & P04 where you need more accuracy go with Lamotte for N03 & Seachem for P04.


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## skylsdale (Jun 2, 2004)

LaMotte is the most accurate you can purchase...followed by Salifert (and much more economical). Anything else is getting you fairly close in the ballpark, but not necessarily that specific reading.


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## TWood (Dec 9, 2004)

The AP NO3 and PO4 kits are every bit as accurate as the Lamotte and other high priced kits. They are just not as precise. The AP NO3 kit can report 5 or 10ppm for example (among other readings) while the LaMotte can supposedly give a reading like 7.5ppm. Does it matter? No. I can extrapolate the AP readings close enough when the color falls between the charted values so that the AP kit ends up being at most 1-2ppm off in precision. Way more precise than we really need anyway.

IMO

TW


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## trenac (Jul 16, 2004)

I disagree my AP N03 gave me a reading of 20-25ppm when the Lamotte gave me a reading of only 8.8ppm, for me that is a big differance. However with that said you can use the test kit you feel is right for you.


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## TWood (Dec 9, 2004)

User error.

TW


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## MatPat (Mar 22, 2004)

I think pretty much anything other than Lamotte or Hach is only going to give you a ballpark range. 

I agree with TrenaC as I have had some quite different results between my Seachem NO3 and PO4 test kits and the Lamotte NO3 and PO4 kits. I tossed my Seachem kits in favor of the Lamotte's. In my experience, you get what you pay for. 

Just recently I took some water into my LFS as a result of some Cardinal deaths. Their water test showed my pH at 7.6 (6.6 in the tank), NO3 at 40ppm (8.8 Lamotte) and PO4 at zero (1.5 Lamotte), KH at 13.4 dKH (7dKH using AP kit). They were using some type of Dip Stick, I don't know (and don't care) what brand as it seems it isn't accurate.


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## Bavarian3 (Oct 21, 2004)

trenac said:


> I disagree my AP N03 gave me a reading of 20-25ppm when the Lamotte gave me a reading of only 8.8ppm, for me that is a big differance. However with that said you can use the test kit you feel is right for you.


wow....thats a huge difference. What would u guys say the closest is to lamotte without the big price tag?


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## trenac (Jul 16, 2004)

IMO, you pay for what you get... I learned this the hard way by buying 3 differant brands all giving differant readings and one reagent always running out before the other. Since they had no refills available buying a new test kit was the only way to go. After doing this several times I could have bought a Lamotte the first time and saved money.


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## BigFoot (Jan 3, 2005)

I use seachem for no3 and po4 hagen for ca,gh,kh.


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## Bavarian3 (Oct 21, 2004)

trenac said:


> IMO, you pay for what you get... I learned this the hard way by buying 3 differant brands all giving differant readings and one reagent always running out before the other. Since they had no refills available buying a new test kit was the only way to go. After doing this several times I could have bought a Lamotte the first time and saved money.


yeah..i wonder what the guy at the lfs was using ill have to ask and see. PH is definetly somethign i cant mess with and i need to know exactly what it is (african cichlid tank). What would u recommend below lamotte if u had to?


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## trenac (Jul 16, 2004)

I have heard of _Salifert _being compared to Lamotte, at about half the cost.

http://www.marinedepot.com/aquarium_test_kits_salifert.asp?ast=&key=


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## TWood (Dec 9, 2004)

Test the test kits if you are unsure of their accuracy.

I used; http://www.csd.net/~cgadd/aqua/art_plant_dosage_calc.htm

to mix up a solution of 1/8 teaspoon KNO3 in 200 ml of water and dose a gallon of clean water in calculated increments for 5, 10 and 20ppm NO3. The Aquarium Pharmaceuticals NO3 test kit accurately reported results that were identical to the calculations.

Not bad for a kit containing 90 tests and only $7 off the shelf at the local big box. I understand that the gadgets associated with an aquarium are part of the fun, but any insistance that only high-priced test kits will do is just wrong. It is also particularly damaging to newcomers who might forego testing altogether when mislead into believing that they have to spend so much on high priced test kits. It ain't rocket science.

IMO

TW


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## skylsdale (Jun 2, 2004)

> What would u guys say the closest is to lamotte without the big price tag?


I answered that on p. 1 of the thread.



> The AP NO3 and PO4 kits are every bit as accurate as the Lamotte and other high priced kits. They are just not as precise.


Do you mind explaining the difference between accuracy and precision?



> The AP NO3 kit can report 5 or 10ppm for example (among other readings) while the LaMotte can supposedly give a reading like 7.5ppm. Does it matter? No. I can extrapolate the AP readings close enough when the color falls between the charted values so that the AP kit ends up being at most 1-2ppm off in precision. Way more precise than we really need anyway.


In the reefkeeping hobby, you need results to be as accurate as possible. So yes, it DOES matter.


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## MatPat (Mar 22, 2004)

TWood said:


> Not bad for a kit containing 90 tests and only $7 off the shelf at the local big box. I understand that the gadgets associated with an aquarium are part of the fun, but any insistance that only high-priced test kits will do is just wrong. It is also particularly damaging to newcomers who might forego testing altogether when mislead into believing that they have to spend so much on high priced test kits.


True, $7 isn't a bad price for a test kit, but buying it from my LFS or Big Box store scares me as most kits in this price range don't have an expiration date. Have you ever noticed the amount of dust on top of some of these kits? I feel better calling Lamotte and having them ship me a kit. While it could've sat on Lamotte's shelf just as long as in a LFS, I just somehow doubt that it did.

As far as accuracy, I have found that the 5ml line on different AP test tubes aren't at the same levels. So which one is correct? I purchased a 5ml syringe from a pharmacy and as it turns out, neither of the lines is 5ml! The Lamotte tubes measure right at 5ml. I have two AP pH test kits with the same lot number. Each kit gives me a different reading when I check my pH. Which is right? Who knows, but if I don't get a controller in the near future I will probably get a pH pen. Not because it is needed, but because I would like to "know" what my pH is, not guess, and the LFS isn't much help when measuring pH. By the time the sample gets to the store, the CO2 has already outgassed.

When I first got my Lamotte PO4 kit I ran 3 tests, a Lamotte, a Seachem, and a Red Sea. All three kits gave me a different reading. To make things worse, after adding the reagents to the Red Sea kit, there wasn't much room left in the tube to "mix thouroughly" as the directions stated.

I also find it much easier to read the Lamotte since the Octet comparator has the colors right next to the vial, in a solution. I don't have to try and match the color of a solution to the color that was printed on a piece of paper and then laminated. I have also noticed that the colors printed on some test kits don't always match each other.

Like TrenaC mentioned, if I would've put down the money on Lamotte initially, I could've saved myslef a lot of money of trying out different test kits. I too spent alot trying to find a kit that was easy to read and accurate.

I think the last thing anyone would want to do is discourage someone who is new to the hobby. Everyone is trying to help and merely stating their opinions. There is a qoute about opinions that I heard somewhere: "Opinions are like @ssholes, everybody has one and they all stink"

I was asked for mine and I merely gave it. Sorry if you thought it stunk


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## Mnemia (Nov 23, 2004)

For the meaning of the terms accuracy and precision, read this: http://en.wikipedia.org/wiki/Accuracy_and_precision

It's actually a pretty decent explanation of the key difference in these terms as they are used scientifically.


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## TWood (Dec 9, 2004)

MatPat said:


> There is a qoute about opinions that I heard somewhere: "Opinions are like @ssholes, everybody has one and they all stink"
> 
> I was asked for mine and I merely gave it. Sorry if you thought it stunk


Nah, not at all. But I'm the lone voice on this test kit thing, so I tend to speak a little louder to get heard. I don't know about the other el cheapo test kits, but I do know that AP kits are good for my needs. Test the test kit itself if you don't believe me.

Regarding age, when my last AP kit was about to run dry I bought a new one and compared results between the two. The older kit, which at that time was two years from being off the shelf, gave the same result as the new one. Proper use and storage are important.

The way I view accuracy and precision in this context is in the way the values are reported. The AP kit has readings for 5 and 10ppm (among others) for instance. If it reports 5 or 10ppm when the test subject is in fact 5 or 10ppm, then it is accurate. The LaMotte can slice that a bit finer and report, let's say, 7.5ppm. That's more -precise- because it's making a finer distinction. But I can look at the AP chart and interpolate the color myself if it falls between 5 or 10ppm. So if I guess at 7-8ppm because the color is halfway between 5 and 10, I've come to the same result for a fraction of the cost.

TW


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