can ammonia and nitrite readings ever reach 0?

[mikemou]

Not to hijack the 'Red Tail Dead! Sand 8.0 pH ?!?!?!' thread, I started a new one here.

The issue was brought up in the other thread that whether it's 'possible' to have both ammo and nitrite 0, or in other words undetectable. From what I gathered on this forum, the answer is a positively yes, and those zero readings are the indication of a cycled tank.

Would you offer your insights to educate a curious mind?

 

[AtodaJ]

imho (h = humble)

Of course the answer is technically no. There will always be trace amounts of ammonia as your fish are always "relieving themselves" all over the place... hehe.

With that said, a properly cycled tank with a healthy biological filter will consume the ammonia fast enough such that you will not register any detectable readings from a proper aquarium test kit. If you do register a noticable ammonia level then there is an issue that requires addressing unless you already are aware of the reasons and have it under control (e.g. you introduced a few new fish and are waiting for you biological filter to catch up to the increased bio load).

Hope that helps.

 

[Menagerie]

The reason both should be undectable is due to the beneficial bacteria in your filter processes the ammonia (from waste) and converting to nitrite. Then another bacteria takes the nitrite and converts it to nitrate. Nitrates (plant fertilizer) are generally tolerated by the fish up to 40ppm.
The nitrogen cycle: http://www.aquariumadvice.com/showquestion.php?faq=2&fldAuto=21

 

[QTOFFER]

Well, there is 0 ppm ammonia/nitrite and then there are undetectable levels of these toxins.
In my mind, these are two very different things.
When a tank is cycled, I believe you see undetectable levels. If the ammonia ever really went down to 0 ppm, wouldn't the nitrifying bacteria die for want of food?

 

[smilla4]

Well, there is 0 ppm ammonia/nitrite and then there are undetectable levels of these toxins.
In my mind, these are two very different things.
When a tank is cycled, I believe you see undetectable levels. If the ammonia ever really went down to 0 ppm, wouldn't the nitrifying bacteria die for want of food?

Oh you're so technical!!

EDIT: (By the way I am ribbing you, I wan't trying to be obnoxious or rude)

 

[Christmasfish]

Hahah! Touche' QT!


>*shakes head wryly*<

My check kit is zero or up there. When I am really wondering I use the expensive kit I bought before I realized that pet stores carry simpler ones....
With most nice aquarium kits, if it is undetecable I think you can say "Zero" with good concious...

 

[QTOFFER]

Well, there is 0 ppm ammonia/nitrite and then there are undetectable levels of these toxins.
In my mind, these are two very different things.
When a tank is cycled, I believe you see undetectable levels. If the ammonia ever really went down to 0 ppm, wouldn't the nitrifying bacteria die for want of food?

Oh you're so technical!!

EDIT: (By the way I am ribbing you, I wan't trying to be obnoxious or rude)

*grin* Heh, I probably posted that after another long conversation with my boss about instrument sensitivity. In the lab where I work, this issue of something actually being present vs it being detectable comes up all the time.