Hello;

I'm starting up a new aquarium, and am using the fishless cycling method to get it ready for the first fish.

I added an amount of clear ammonium hydroxide solution, and measured the ammonia level using the ammonia test from an API freshwater Master Test Kit. It was off the charts. I did gradual water changes until I got the ammonia level down to ~5 ppm.

Just to verify, I also tested with a Salifert ammonia "NH4 Profi Test". This test shows an ammonia level of ~0.8 ppm.

From Googling I understand that Salifert is generally considered to be a more accurate test kit than API, but this is a huge difference in readings. The Salifert test kit has an expiration date of Sep 2013. The API ammonia bottle #1 has a lot number of 83B1011 which I understand to mean that it was produced in Oct 2011, and the solutions should have a shelf life of three years.

Anybody have a clue as to what might be going on here? Thanks in advance.

Most of us here use the api kit you are talking about and praise it for its accuracy. As a matter of fact I have never heard of the Salifert test you are talking about.

If it is a strip however I wouldn't trust it, most strips are well known for inaccuracy.

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It's not a strip; it's a liquid-regent based test which is generally ranked pretty highly, including among marine aquarium hobbyists who are usually even more meticulous about water parameters than are freshwater hobbyists.

Did you make sure it was a freshwater test kit? I know it seems like a strange question, but I went to salifert website and their page for freshwater was under construction. That makes me nervous. Their saltwater tests look pretty damn good I will say though

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Yes, the included instructions say "the ammonia test can be used for both marine and fresh water".

Test again.

I would re test and be sure to shake the bottles real well, I've gotten wonky results before from not shaking enough.

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"Being ignorant is not so much a Shame, as being unwilling to learn".-- Benjamin Franklin

API you should shake them up for a bit, then wait 5 mins for results. I use API. No issues. Salifert from what I hear is a good test kit also, more accurate than the API is.

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Tested again today, same results.

I also tested a sample of my tap water with both kits, which both showed 0 ppm.

I was wondering about that. The instructions say nothing about shaking the bottles, so I was a little leery about this. I did shake them a bit before my last test; tomorrow I'll shake the bottles well before repeating the test.

Same results. :-(

Don't dose the tank anymore, let it run it course now. You jump started the cycle, sounds like to much was used per gallon is all.

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Thanks, I just wish I felt like I had an idea of which ammonia level is correct, as I'm going to need to know when it hits zero.

I'll monitor for nitrites, which currently reads 0 according to my API kit.

I'd say use your API kit, if you 've tested it a few times, its correct. Use that info. Its possible you have a bad test kit, but its on the highly unlikey side of it. Watch your Nitrate levels,not the Nitrite levels if in doubt. The lower the Trates get the safer you are.

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Well, I've also tested the Salifert kit a few times too. ;-)

Not sure I understand, here. As a result of fishless cycling, all I'll have is increasing nitrate levels. What would lower the nitrate levels other than water changes?

Thanks in advance.

I think the reason you're encountering problems here is that the API test kit detects both ammonium (NH4) and ammonia (NH3), whereas the Salifert kit seems to only detect ammonia. I've heard two conflicting things about ammonium. 1: It is more toxic to fish but is rarely encountered in the aquarium world, 2: Ammonium is non-toxic to fish. Not sure which, but either way, I think the detection of ammonium vs. ammonia is the difference between API and Salifert. I've also heard that decomposing bio-matter generates ammonia or ammonium depending on the pH level. Whether it makes a difference remains my primary doubt. However, I would stick to the API kit just because I'm unsure whether ammonium poses a threat.

Sources:
Fish Poop and You: A Primer
The Aquarium Nitrogen Cycle

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Officially fishless until after the move....tune in later for details!

According to the Salifert test kit kit instructions, "the values on the color chart are in mg/L total ammonia (that is NH3 + NH4)."

I stand corrected. Thanks

Maybe take a sample to your LFS and have them test it as well? 3rd opinions are always good.

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Officially fishless until after the move....tune in later for details!

Yep, and that'd be cheaper than buying a third test kit. ;-) Thanks.

I really don't know except that some nitrates test kits are calibrated to measrue the entire ion and some are calibrated to measure only the nitrogen part.

Is it possible that ammonia kits are the same?

Also the api test kit measures both the locked and free ammonia. So it could be possible the salifert only measures the free ammonia. If true the difference is the locked ammonia.

just guessing.

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fw leiden since 1979, fo salt since 1979, mixed reef 55g 2002-2009. Strong emphasis on the tank taking care of itself. Balanced with plant life, no water changes, tap water, no filters in FW. Only dosing calcium, alk, mag in marine reef tanks. http://www.aquariumforum.com/f15/my-...ods-26410.html
recent tanks (till 2009) 7 years- 10g FW leiden 7 yrs, 55g mixed reef 7, 2 yrs, 20g FW leiden, 10 g fw leiden , 29g mixed reef, current tank 55g leiden