No Nitrates In Established Cycled Tank?

[ShamefulCrayon]

Hello all

I've tested my tank again today and found the nitrates at 0ppm again. That's what it's been at mostly since I put an anubia in there and cycled it a few more times.

My readings today on my 22L nano cube:
Ammonia - 0ppm
Nitrites - 0ppm
Nitrates - 0ppm
Ph - 7.6

I know it's definitely been cycling as on the 8th of October the readings were
Ammonia - 0.25ppm
Nitrites - 0.25ppm
Nitrates - 5ppm

My question is - should the nitrates ever be at 0ppm? I've heard of heavily planted tanks sometimes having 0 nitrates but it seems weird it could happen in my tank as there's one large anubias and one other short reddish plant. Should I be worried?

 

[Byron]

I certainly would not worry.  Nitrates at zero with plants is not uncommon, it tends to depend upon the fish load; the more fish, the more likely you will have some nitrates though with lots of plants these will be very low.
 
Slow-growing plants like Anubias are obviously not going to take up nutrients (including ammonia/ammonium) as much as fast-growers (stem plants and floating plants are especially good for this), but if there are no fish present, it is possible your plants are utilizing the ammonia which is now occurring (there will be some even with no fish present, though it may not be detectable with test kits) and thus nitrite is not occurring and thus nitrate is not occurring.  Your reddish plant is likely a larger consumer of nutrients.
 
Byron.

 

[ShamefulCrayon]

Thanks Byron, that's reassuring. I have one Betta in the tank at present. He's very active and usually comes to greet me at the front of the tank when I get close so I'm not worried about his health. I can relax about the water now too.

Charley

 

[eaglesaquarium]

I'd also mention that unless you do some serious serious shaking of the bottles (API test) then you may be getting false readings.  

 

[ShamefulCrayon]

Thanks Eagles aquarium, I always make sure to give the bottles about a 30 second shake before I open them.

 

[eaglesaquarium]

Thanks Eagles aquarium, I always make sure to give the bottles about a 30 second shake before I open them.

 
That might actually be the problem then.  As the bottles age, they need more and more shaking.  I tend to pound the bottle on the table a few times, then shake it for a full minute plus.  ( I also only do the test about every 3 months or so.)

 

[ShamefulCrayon]

An, this I didn't know. I do however test the water every three days to keep an eye on the cycles as it's only been cycling for about 3-4 months. I'll give the test bottles a rougher time next time and see if it makes any difference.

 

[eaglesaquarium]

The reagent in the nitrate #2 bottle is actually a solid that needs to be reintroduced each and every time.