Inaccurate test kit??

[FishionistaB]

Hello all.
I’m doing a fish-in cycle rn with seachem prime on my new 65 gallon tank. Everything going great so far, fish very happy, tank looks beautiful, very happy. Well I decided to test my tap water with my API freshwater “master test kit” today and it’s showing my tap water at ~.75 ppm on ammonia. Is it possible it’s actually catching ammonia (or ammonium) in my tap water? I’ve heard these test kits in particular may not be the most accurate? The only other thing I can think of is maybe some of the tank water droplets are In The test tubes when I’m testing? But if that were the case wouldn’t expect it to test so high... Which do you think is more likely the scenario here? I plan on getting a better test kit soon. But meanwhile, I’d appreciate some input

 

[kwi]

If you get an off the wall result retest twice.
Make sure you rinse your test tubes well, 3 times is the minimum.
Re read and follow instructions to the letter.
But yes you can get ammonia in tap water.

 

[HoldenOn]

Yep, as kwi says you can read al sorts of things in tap. I have about .25 nitrite in mine.

 

[Ch4rlie]

The API test kit tends to be fairly reliable as long as instructions are followed to the letter.

Dirty test tubes can contribute to false readings.

Water in test tube must be accurately measured to the white line.

Finger over the test tube rather than the stopper can give wrong readings due to cross contamination

You must shake the reagent solution bottles particularly hard, not just a quick shake. This reactivates the solution before adding to water in test tube.

Taking sample of water from tank, if you use a dropper or pipette, endure this is clean.

Taking sample of water from tank, ensure you take a sample from at least 2 inches below the water surface, not just from surface.

Make sure you add exactly the correct number of drops, too many or too few will give false readings.

That’s just to name but a few things, all these above can contribute to false / wrong readings so it pays to be careful.

There are more accurate freshwater testing kits available but they tend to be more expensive, there is Salifert test kits which comes in individual packets and in powdered form, more expensive and think it’s more geared towards the saltwater fishkeeping section, is fairly accurate as well, I’ve never tried it though.

If you want top notch accuracy, nothing tops laboratory test kits which are in many different forms and equipment which can run into hundreds if not thousands, not economically viable for most keepers.

This is why we normally recommend API test kit, pretty reliable and accurate for the hobby as well as being good value compared to other test kits available.

I’ve tried different test kits and always seem to prefer the API kit as it’s actually a pretty good package and easier for testing than others.

If you do find a better test kit, do post your opinions and costs on here, I’d be really really interested in hearing more about this.

 

[Essjay]

Salicylate ammonia testers test for total ammonia - that's ammonia and ammonium combined. These exists in water in an equilibrium and the amount of each depends on the temperature and pH of the water. At low pH most of the total ammonia is in the ammonium form, while at high pH more is in the ammonia form. Most brands of liquid reagent testers are salicylate testers.

If your water provider uses chloramine there will be a reading for ammonia in your tap water. Chloramine is ammonia and chlorine joined together and the ammonia tester reads this ammonia.

 

[FishionistaB]

Thank you all for your input. I have Always rinsed the tubes super duper well and made sure the water was as close to exactly at the 5 ml line as possible; so thinking that’s less likely the cause. I did another test on the tap water AFTER adding a drop of prime; the water then tested NEGATIVE for ammonia!!! I’m guessing the chloramine picks up as ammonia (does anyone know)? So yay. Since I’ve been every day- every other day dosing with prime I’m a lot more confident that I’m getting accurate readings directly from my tank. I work in vet med so getting a pipette will be easy and will def use that from now on a little deeper in the water. Lastly, after doing a little digging and researching yesterday; I feel pretty confident that the only thing I need to make this test kit more reliable is the ammonia multikit from seachem that tests for free and total ammonia. Until it gets in I will test daily with the API kit and will let you all know if anything is going awry.

 

[Essjay]

From the FAQs on the Prime page of Seachem's website

Under the conditions of a salicylate kit the ammonia-Prime® complex will be broken down eventually giving a false reading of ammonia (same as with other products like Prime®), so the key with a salicylate kit is to take the reading right away.

 

[FishionistaB]

If your water provider uses chloramine there will be a reading for ammonia in your tap water. Chloramine is ammonia and chlorine joined together and the ammonia tester reads this ammonia.

ah ok, I’ve been reading about that. My confusion lies in the breakdown. After you add the prime the chlorine portion is gone and you’re left with ammonia or ammonium (I’m not sure which) but either of those would test pos for ammonia, correct???
If this is true; why then would my tap test neg for ammonia after adding the prime???

 

[FishionistaB]

You must shake the reagent solution bottles particularly hard, not just a quick shake. This reactivates the solution before adding to water in test tube.

so in my instruction manual it doesn’t say to shake the bottles (other than nitrate #2) I have been following the instructions to a T so I haven’t been shaking them before testing (other than nitrate #2) should it be a vigorous shake or more of an inversion to get the product more even?

 

[Ch4rlie]

In all solution bottles I always give them a good shake, particularly the nitrate #2, this is good practice to do so as it activate and distributes the solution evenly throughout.

Gives less chance of wrong or inaccurate readings imho.

 

[Essjay]

ah ok, I’ve been reading about that. My confusion lies in the breakdown. After you add the prime the chlorine portion is gone and you’re left with ammonia or ammonium (I’m not sure which) but either of those would test pos for ammonia, correct???
If this is true; why then would my tap test neg for ammonia after adding the prime???

If your tap water shows no ammonia but the tank water shows above zero, the ammonia must be being made by the fish in the tank. As you are doing a fish-in cycle, you don't yet have enough bacteria to remove all the ammonia made by the fish.


How long have there been fish in the tank, and have you ever had a reading for nitrite?

 

[FishionistaB]

Fish have been in for about a week and a half. I’ve been taking measurements of ammonia, nitrite, and nitrates almost every day. We’ve had all three at varying degrees since about 5 days in. I’ve been following guides I’ve found on here and elsewhere and keeping a mental journal of the levels. Just performed my first water change last night.

My tap water tests positive For ammonia before the prime but negative after adding the prime. So assume the levels I’m getting are true? I’m adding prime every-every other day to keep the fish safe and they seem very happy so far. only one death but that was from injury during capture and not tank conditions.

I guess my biggest confusion so far is that my nitrites started testing pos about 5 days in. They steadily started rising (again I’m following the guides to make sure they’re acceptable levels, performing water changes when combined ammonia, nitrites reach a certain level, adding prime, etc), and then yesterday after the water change my tank tested pos for ammonia, and somehow negative for nitrites for the first time since day 5.
I know ammonia is needed for the cycle and I’m taking every precaution to make sure I’m doing it the right way. But, given this info... did I fudge something up??? Or it’s just a part of the cycle