Aquarium Co-op test strips vs API test kit question

[LoachTruther]

Hi everyone, I've been using my Aquarium co-op test strip for about two weeks now and I'm loving them, but I've noticed the readings I get with them are different than the ones I get with my API test kit (not the strips, the tubes). I'm more inclined to trust the test strips than the API kit because I know how much testing goes into Aquarium Co-op products, but I was wondering if anyone had similar experiences, and what ended up happening.

[tolstoy21]

I find every test kit I use reads different from their competitors’ kits to varying degrees.

[Jayci]

I used both at the same time, and from what I saw, both of my kits showed the same ballpark water parameters. I'm tempted to find out which is more accurate, but that would require me taking water samples to a county water treatment facility and for a price.

Overall, I'm sticking with the Co-ops strips due to value and that the colour chart is better. The API chart is a double sided peel out, and once the adhesive stops working, the label flaps around. Yes, it's such a minor detail, but it's enough to make me switch to the Co-op strips.

Just go with whichever brand you feel is best! Both seem reasonably accurate.

[awymorePDX]

How far apart are they? I've noticed a pretty big difference between my strips and liquid kit.

[LoachTruther]

25 minutes ago, awymorePDX said:

How far apart are they? I've noticed a pretty big difference between my strips and liquid kit.

Different parameters read differently, ammonia reads as barely different, but nitrates are sometimes 50 ppm apart or more

[GardenStateGoldfish]

Against popular belief, I find the API liquid test kits to be inaccurate due to human error a lot. Not saying you did anything wrong, but drop sizes can vary, tube fill amounts can vary, the Nitrate test needs to be banged and shaken like crazy to be accurate from bottle two and the Ammonia test is NH3 and NH4 which really reads ammonia and ammonium, not just ammonia so it does not give an accurate ammonia reading, you need to calculate it yourself based off temp, PH and NH3+NH4. 

In other words, I prefer test strips, just dip and read, takes user error out. 

[awymorePDX]

I don't have the ammonia test strips, but it makes sense that they would be close as ammonia is pretty much a constant value in a correctly cycled tank.

I see my biggest differences in the PH, I need to do another AB test, but they have been more than 1 point different

[LoachTruther]

47 minutes ago, awymorePDX said:

I don't have the ammonia test strips, but it makes sense that they would be close as ammonia is pretty much a constant value in a correctly cycled tank.

I see my biggest differences in the PH, I need to do another AB test, but they have been more than 1 point different

Oh yeah I forgot to mention, the pH readings using the API test kit are always significantly more basic than with the strips. It would make sense that the strips are more accurate though, I’ve been losing my mind trying to figure out what is bringing up the pH in my tank, but the strips put it at just barely below neutral. That reading makes more sense given that tap water is neutral or ever so slightly basic, and the nitrogen cycle brings the pH down

[Cory]

I suspect lots of this comes down to testing methods, possible contamination, not waiting correct times etc. The strips were tested vs known scientific solutions. They were right on. Then we tested with sterilized API kits, and digital meters. All were very close in our testing, which was done by myself, Randy, and Dean. We also had the store using them for a few months before going into production. I don't want to stifle people's tests. By all means keep testing etc. I think the test strips are accurate, especially for the level that an aquarist would need.

[Hobbit]

I’ve found my coop test strips and my API test kit to be fairly similar, though I haven’t compared them extensively. I do see differences, but they’re within the range of “I can’t quite make out what color this is” errors.

[Celly Rasbora]

Coincidence! I just looked at the object I am working on, a digitized page out of a notebook from a 1920s era nursing student:

"Litmus paper …
If it turns paper blue alkali
If it turns paper pink acid."

Oh, if only the colors were that obvious! As Hobbit says, I struggle a lot with determining the right color, especially for the API nitrate test. I bought a container of Tetra test strips on Amazon, but I look forward to running out so I can justify buying Aquarium Co-Op's test strips.

[tolstoy21]

27 minutes ago, Celly Rasbora said:

As Hobbit says, I struggle a lot with determining the right color, especially for the API nitrate test.

I like and trust the API liquid test kits to a degree, but I have this same difficulty with the colors of the Nitrate and with the high Ph colors.

For me, personally, if a test gets me in the ballpark, I'm happy with it.

What I look for in a test is that it's consistent between readings in a water sample that hasn't changed. This way when I take two readings I can be like OMG that was light orange yesterday and now it's deep red, something is up!

I use test strips more often than liquid kits, and with these, I'm just looking at trends -- how much has the color changed for any given thing since last reading, and in which direction is it headed -- up or down.

I stopped trying to differentiate between the shades of color for something like 10ppm vs 20ppm nitrate, or 6.6ph vs 6.8ph. However, if Ph was lightish green and now it's a deeper blue, that's meaningful enough for me.

I am eager to try the Coop strips, as the price is good deal for the quantity of strips.

[LoachTruther]

13 hours ago, GardenStateGoldfish said:

Against popular belief, I find the API liquid test kits to be inaccurate due to human error a lot. Not saying you did anything wrong, but drop sizes can vary, tube fill amounts can vary, the Nitrate test needs to be banged and shaken like crazy to be accurate from bottle two and the Ammonia test is NH3 and NH4 which really reads ammonia and ammonium, not just ammonia so it does not give an accurate ammonia reading, you need to calculate it yourself based off temp, PH and NH3+NH4. 

In other words, I prefer test strips, just dip and read, takes user error out. 

I'd never thought of this but you're absolutely right, there's a lot more room for human error with the liquids test kit, especially if the test solutions get contaminated, or if the water partially evaporates off and changes the concentration

[Will Billy]

I have to agree with @tolstoy21 on this one. My aging eyeballs has difficulty telling 40ppm and 80 ppm nitrate. (Which has often made me wonder how a person who is legitimately color blind navigates this issue.) Ball park readings is what i am mostly going for. Any drastic changes are my alarm bells that tells me something is wrong. I also will admit that i dont have very fussy fish. I could see where more delicate fish with larger margins of error could come into play, but again if your new test strips are accurately reporting consistency or lack there of, i feel like it is doing what it was intended to do. 

[JmDenny]

Does the Aquarium Coop test both NH3 and NH4? I understand the API master does both.

[Pepere]

I could never gain any confidence in the ammonia strips. 
 

I had water that was dosed with ammonia chloride to 4 ppm ammonia that read zero or trace on strips and 4 ppm on api tube test.  Likewise dosing distiled water as a control yielded similar results.

 

and when I had a tank with a natural spike of 2ppm during natural cycling not dosed with Ammonia chloride the test strip still did not register.

Aquarium co op was kind enough to send a replacement bottle to see if first bottle was defective, and results were the same for me.  I tried dozens of the strips varying how aggressively I swirled the strips and varying the waiting time to read them.  I simply could not get to the point of having confidence in a negative test being accurate.  I just dont want to think I have 0 ppm when I actually have 2-4 ppm.

 

in practice though I will admit once past initial cycling, I find it far more likely to test zero ammonia with some nitrite present than to see some ammonia and zero nitrite.

I have decided to stick with the test tube kits for both ammonia and for the ph, nitrite, nitrate as well as gh kh.  Seeing test pads that are not a uniform color across them is rather annoying as well.

I carefully fill the tubes with a syringe, and test Ph, ammonia, nitrite and nitrate ensuring bottles are vertical and care to get uniform drops.  I grant that distinguishing between 40 and 80 ppm nitrates is tough, but anything over 40 ppm nitrates is going to get a water change in my tank so the difference is irrelevant.

 

[Colu]

I have used API ammonia test strips and it always gave a reading of zero when cycling my tank and my API  liquid test kit was giving a reading of 3ppm I have had the same experience with a couple of brand's of ammonia test strips over the last 10 years complete waste of money I only use liquid test kits for ammonia testing now

Edited August 28, 2022 by Colu

[Pepere]

On 8/28/2022 at 11:03 AM, Colu said:

I have used API ammonia test strips and it always gave a reading of zero when cycle my tank and my API  liquid test kit was giving a reading of 3ppm I have had the same experience with a couple of brand's of ammonia test strips over the last 10 years complete waste of money I only use liquid test kits for ammonia testing now

Well it feels good to hear other people having similar results.

And with a cost of around $15.00 for just the API Ammonia test kit or $22.00 for the master test kit, the master test kit seems to make more sense to me.

[Cleveland M]

On 8/28/2022 at 10:13 AM, Pepere said:

And with a cost of around $15.00 for just the API Ammonia test kit or $22.00 for the master test kit, the master test kit seems to make more sense to me.

Same here but I probably going to end up with some expired reactants.

[face]

water testing is extremely prone to miss reads almost all tests have more interferences than you can imagine and most don't directly measure the thing you think they do and on top of that some might read in different units nitrate  or nitrate nitrogen being 4.4x different for example 

ammonia for example gets messed up by iron calcium magnesium nitrate nitrite water conditioner chlorine and very acidic water and more it can also depend on the ammonia test method.

nitrate tests don't even test nitrate they turn the nitrate to nitrite  and test that the amount of nitrite converted is small 1 or 2 % so any nitrite in the water can read as 50 to 100x nitrate some are better than that but still  than there's shacking api bottle 2 needs to be shaken a lot the test tube needs to be shaken to to much shaking and it will read high to little and it will read low there's also other chemicals that interfere.

api 2 after being shake for 30 seconds still not mixed

kh doesn't actually test kh it test buffing capacity the amount of acid it takes to lower the ph down to a set amount normally around 4 you can have high kh with no carbonate or bicarbonate in your water.

gh can thrown off by pretty much any mettle making it a different color than its supposed to be 

and there's so much more that i don't have time for right now tests are a ballpark things especially when you factor in human error see brs testing different tests and pretty much getting different results every time even from the same test kit done by different people.

Edited August 28, 2022 by face
i just realized this post is a year old lol oops

[rockfisher]

I have had issues with the aquarium co- op strips. They tried to help but nothing really helped. The liquid test was more accurate. I think its due to my well being super high in Mg.

[Patrick_G]

On 8/28/2022 at 9:54 AM, face said:

water testing is extremely prone to miss reads almost all tests have more interferences than you can imagine and most don't directly measure the thing you think they do and on top of that some might read in different units nitrate  or nitrate nitrogen being 4.4x different for example 

ammonia for example gets messed up by iron calcium magnesium nitrate nitrite water conditioner chlorine and very acidic water and more it can also depend on the ammonia test method.

nitrate tests don't even test nitrate they turn the nitrate to nitrite  and test that the amount of nitrite converted is small 1 or 2 % so any nitrite in the water can read as 50 to 100x nitrate some are better than that but still  than there's shacking api bottle 2 needs to be shaken a lot the test tube needs to be shaken to to much shaking and it will read high to little and it will read low there's also other chemicals that interfere.

api 2 after being shake for 30 seconds still not mixed

kh doesn't actually test kh it test buffing capacity the amount of acid it takes to lower the ph down to a set amount normally around 4 you can have high kh with no carbonate or bicarbonate in your water.

gh can thrown off by pretty much any mettle making it a different color than its supposed to be 

and there's so much more that i don't have time for right now tests are a ballpark things especially when you factor in human error see brs testing different tests and pretty much getting different results every time even from the same test kit done by different people.

Good point made!  

@face, do you have a bio or chemistry background? I'm not trying to call you out, I totally agree with your post. It’s just nice when we have chemists participating in the forum. 

[_Eric_]

Ive use both but find the API is more of my go to.   I’m more interested in checking to see if I have a small amount of nitrite or ammonia popping up and it is easier for me to see that on the api.  For nitrate, I like to keep between 20 and 40 and easier for me to do that with the scale on the api.  Results seem similar to me but I have to take the reading right at 60 seconds for the test strips - color changes quickly after that in my experience with my water.
 

Nice to have gh and kh though.  That doesn’t seem to change for me that often (my tap water changes throughout the year but it doesn’t bounce too much week to week)

overall my water is on the higher end for gh and kh and I don’t do anything to try to manage it.  It is interesting info to have though.

[rockfisher]

Has anyone used one of these test

https://www.ebay.com/itm/255662902654?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=AptdVU9zRHK&sssrc=2349624&ssuid=v0AGUAjUSm-&var=&widget_ver=artemis&media=COPY

I wish this had the Mg, and Ca test

 

https://www.ebay.com/itm/255207239258?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=AptdVU9zRHK&sssrc=2349624&ssuid=v0AGUAjUSm-&var=&widget_ver=artemis&media=COPY
 

I’m really looking for a test that has all the things to test for. Has anyone found one.

[face]

On 8/28/2022 at 3:02 PM, Patrick_G said:

Good point made!  

@face, do you have a bio or chemistry background? I'm not trying to call you out, I totally agree with your post. It’s just nice when we have chemists participating in the forum. 

no chemistry background just an idiot that reads too much lol always feel free to correct me if i say something wrong.