Jump to content

Which test kit is correct?


AJE
 Share

Recommended Posts

On 6/20/2021 at 3:05 PM, AJE said:

Interesting. So does this mean just the ph is inaccurate? Can I trust the other parameters? 

I was having a little trouble with nitrate  and hardness at first too.  from what I can tell its really important to set a timer and read at exactly 1 min.   nitrate especially gets darker as you leave it around.

 

You can also see in your photos and mine and many others that if you're not careful you can get a multicolored kh pad.  I'm pretty sure thats interference from the GH reagent. 

 

I've learned to look at the strip and make sure there are no water bridges between the pads after I take it out.  That usually results in gh/kh readings that agree with my titration tests.

 

The chlorine works okay for me inside (1.5 in my tap, 0 in my tank) but doesn't work for me outside.  I have no idea why.  some people have guessed hose water gets less air and has more choline, or that its the plastic in tubs,  maybe its UV from the sun somehow.  idk.

  • Like 1
Link to comment
Share on other sites

  • Administrators

What is the hardness of your water @AJE From the April picture, and these pictures it looks like it may have changed. Manufacturer says in either super high or super low hardness can have an effect on the test. This also assumes you're taking the pics at 60 seconds etc.

Link to comment
Share on other sites

On 6/21/2021 at 1:38 PM, Cory said:

What is the hardness of your water @AJE From the April picture, and these pictures it looks like it may have changed. Manufacturer says in either super high or super low hardness can have an effect on the test. This also assumes you're taking the pics at 60 seconds etc.

Around 161 according to api test kit. And I have been setting a timer and watching it the whole time keep an eye on the color changes.

Edited by AJE
  • Like 1
Link to comment
Share on other sites

On 6/23/2021 at 8:54 PM, AJE said:

@CT_Should I trust the ammonia, Nitrate and nitrite reading? I don't have api test kits for those anymore.

I've found nitrate to be pretty good. my nitrite is always 0 so either it's always zero or the test is broken, I've never tried to validate that one.  and I should, but i don't check for ammonia 😳.

  • Like 1
Link to comment
Share on other sites

  • Administrators

I’m not sure yet. Honestly I had a busy weekend and the manufacturers labs aren’t open over the weekend so not much progress has been made yet. At the very least we can refund or send another kit to you. However I do t have an answer for you yet on why it’s happening.

Link to comment
Share on other sites

On 6/28/2021 at 12:02 PM, Cory said:

I’m not sure yet. Honestly I had a busy weekend and the manufacturers labs aren’t open over the weekend so not much progress has been made yet. At the very least we can refund or send another kit to you. However I do t have an answer for you yet on why it’s happening.

Ok. I can wait, no hurry. Thanks

Link to comment
Share on other sites

On 6/12/2021 at 7:05 PM, Koi said:

@AJE It looks like theres some extra water dripping from your test strip onto the color chart.

This probably isn't the issue you are running into but I'll just throw this idea out there anyways

Sometimes when I lay test strips flat on a table the water tends to seep through the back and turn the nitrite pad pink (sometimes my ph and kh pads too). Now after I dip my test strips, I just lay it on top of my tongs so that any excess water can drip off without touching the other pads.

IMG_1633.jpg.9916896c29a5f4b11a3c672805679bd6.jpg

This. Same for me, I get weird readings if I leave them laying on something flat.

  • Like 1
Link to comment
Share on other sites

@Cory I did some more testing, this time with bottle water I wanted to see if the problem was something in my tap water. They are still opposites so that eliminates the possibility that my tap water was messing it up, unless the bottled water has the same chemical that is in my tap that would be messing up the test, which I think is unlikely. Next I’m going to buy ro water and see how they compare with that.
Edit: I just noticed that the test strips are just registering the lowest on everything 

8336E726-BD28-4278-97BE-B015F258D56A.jpeg

A091249A-7D36-4A8F-84A5-86F9C8C0ABDB.jpeg

Edited by AJE
  • Like 1
Link to comment
Share on other sites

  • 3 weeks later...

Ok here is the test comparison against ro water. Api is reading 7-7.2ish and coop is 6.4-6.8. So I guess a chemical in my tap isn’t to blame and I just got a rare, faulty coop test kit. I’ll give them another shot and see if I can get one reshipped to me.

2BC152B4-073E-4257-909D-78C55207C57A.jpeg

1ABC1596-F5C1-4E77-9568-D18EA39363FB.jpeg

82F007AB-F00D-4994-91C7-CA22D32ABB55.jpeg

Link to comment
Share on other sites

I got a new test kit in today. Tested out of tap. The old test kit(bottom) shows around 6.8 while the new one (top) shows around 7.6. Also the new one does register a little chlorine (it doesn’t seem to show one camera for some reason) while the old one shows none. The tests do look slightly different in person I guess I have bad lighting or something. Also I tested with the api test kit and the new one is much closer to what it says than the old one. Very happy with the test kit. @Corythought you would be interested.

A337F026-88F4-431F-8D16-6707443357B6.jpeg

7731DDD1-D415-4B77-9A20-49CD5CE4E68F.jpeg

Link to comment
Share on other sites

On 7/28/2021 at 7:58 PM, Cory said:

That is strange, there should have been no difference between those different bottles.

Yeah, very strange, I guess I just got a bad batch the first time. It’s all good now. I really appreciate the easy customer service and all the help. Thanks!

Link to comment
Share on other sites

Hm. My test strips never register chlorine in my tap, and I've wondered if it's the test strip that's off or if my water treatment plant is different (I have no clue and my town is very small/doesn't post reports online). All other parameters on my Co-Op test strips are in line with my API test kit, so it's usually pretty accurate for me.

Link to comment
Share on other sites

On 7/28/2021 at 4:58 PM, Cory said:

That is strange, there should have been no difference between those different bottles.

It would explain my experiment with distilled water and NaOH getting bad results at home but not reproducing in the lab ACO works with.

Link to comment
Share on other sites

@AJE the pH of RO water is really hard to read accurately because it has basically no ions in the solution, and pH indicators depend on ions to read pH. That means any small amount of ions that the tests themselves contain can have a large effect on the readings. So I’m actually not surprised that the coop test strips and the API solution test RO water differently. In this case I’d expect the API test to be more accurate because it’s a larger amount of water with a small amount of test solution compared to the pad on the test strip. But it’s not something I think the coop test strips could necessarily do correctly.

In terms of the readings being weird if you lay the test strip flats @Randall from Texasmentioned—I can tell from the blotchiness of the colors in some of your pictures that sometimes the pads are bleeding into each other. (For instance if the GH pad bleeds onto the KH pad it gives the KH pad dark blue spots.) To prevent this, I always set my test strips on a towel or piece of foam.

Not saying this explains all your problems, but maybe it can help with a few!

ETA: I just realized at least two people already tried to explain this test-strips-bleeding-into-each-other problem, but @AJEit’s still happening to you. I will make a video so you can see what we’re saying.

Edited by Hobbit
Link to comment
Share on other sites

I know people love the strips because so easy. I have found they are never truly that accurate. I stick to test tubes with water and drip chemicals . Old school i know. I personally think they give a more accurate reading then strips. In fact one my local fish store told me they use strips but they are not the top choice for water testing if they had more time. I was also told that out of all 20 plus years of selling fish that non of the so called testers are 100% on money.  I have learned to watch the clarity of my water. When it starts getting grainy or slight cloud then I test. You just know when something fishy is up after keeping fish for a while. No pun intended.  😄

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...